diff --git a/Source/Core/Core/HW/SystemTimers.h b/Source/Core/Core/HW/SystemTimers.h
index 8340047b72..258520ad44 100644
--- a/Source/Core/Core/HW/SystemTimers.h
+++ b/Source/Core/Core/HW/SystemTimers.h
@@ -63,3 +63,12 @@ s64 GetLocalTimeRTCOffset();
 double GetEstimatedEmulationPerformance();
 
 }  // namespace SystemTimers
+
+inline namespace SystemTimersLiterals
+{
+/// Converts timebase ticks to clock ticks.
+constexpr u64 operator""_tbticks(unsigned long long value)
+{
+  return value * SystemTimers::TIMER_RATIO;
+}
+}  // namespace SystemTimersLiterals
diff --git a/Source/Core/Core/IOS/DI/DI.cpp b/Source/Core/Core/IOS/DI/DI.cpp
index 8202a1deeb..6810943699 100644
--- a/Source/Core/Core/IOS/DI/DI.cpp
+++ b/Source/Core/Core/IOS/DI/DI.cpp
@@ -57,13 +57,13 @@ void DIDevice::DoState(PointerWrap& p)
   p.Do(m_last_length);
 }
 
-IPCCommandResult DIDevice::Open(const OpenRequest& request)
+std::optional<IPCReply> DIDevice::Open(const OpenRequest& request)
 {
   InitializeIfFirstTime();
   return Device::Open(request);
 }
 
-IPCCommandResult DIDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> DIDevice::IOCtl(const IOCtlRequest& request)
 {
   InitializeIfFirstTime();
 
@@ -91,7 +91,7 @@ IPCCommandResult DIDevice::IOCtl(const IOCtlRequest& request)
 
   // FinishIOCtl will be called after the command has been executed
   // to reply to the request, so we shouldn't reply here.
-  return GetNoReply();
+  return std::nullopt;
 }
 
 void DIDevice::ProcessQueuedIOCtl()
@@ -612,7 +612,7 @@ void DIDevice::FinishDICommand(DIResult result)
   }
 }
 
-IPCCommandResult DIDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> DIDevice::IOCtlV(const IOCtlVRequest& request)
 {
   // IOCtlVs are not queued since they don't (currently) go into DVDInterface and act
   // asynchronously. This does mean that an IOCtlV can be executed while an IOCtl is in progress,
@@ -623,7 +623,7 @@ IPCCommandResult DIDevice::IOCtlV(const IOCtlVRequest& request)
   {
     ERROR_LOG_FMT(IOS_DI, "IOCtlV: Received bad input buffer size {:#04x}, should be 0x20",
                   request.in_vectors[0].size);
-    return GetDefaultReply(static_cast<s32>(DIResult::BadArgument));
+    return IPCReply{static_cast<s32>(DIResult::BadArgument)};
   }
   const u8 command = Memory::Read_U8(request.in_vectors[0].address);
   if (request.request != command)
@@ -704,7 +704,7 @@ IPCCommandResult DIDevice::IOCtlV(const IOCtlVRequest& request)
     ERROR_LOG_FMT(IOS_DI, "Unknown ioctlv {:#04x}", request.request);
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_DI);
   }
-  return GetDefaultReply(static_cast<s32>(return_value));
+  return IPCReply{static_cast<s32>(return_value)};
 }
 
 void DIDevice::ChangePartition(const DiscIO::Partition partition)
diff --git a/Source/Core/Core/IOS/DI/DI.h b/Source/Core/Core/IOS/DI/DI.h
index f1102016f7..327b50f6d7 100644
--- a/Source/Core/Core/IOS/DI/DI.h
+++ b/Source/Core/Core/IOS/DI/DI.h
@@ -42,9 +42,9 @@ public:
 
   void DoState(PointerWrap& p) override;
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   enum class DIIoctl : u32
   {
diff --git a/Source/Core/Core/IOS/Device.cpp b/Source/Core/Core/IOS/Device.cpp
index 470f1940c8..203787af16 100644
--- a/Source/Core/Core/IOS/Device.cpp
+++ b/Source/Core/Core/IOS/Device.cpp
@@ -160,19 +160,19 @@ void Device::DoStateShared(PointerWrap& p)
   p.Do(m_is_active);
 }
 
-IPCCommandResult Device::Open(const OpenRequest& request)
+std::optional<IPCReply> Device::Open(const OpenRequest& request)
 {
   m_is_active = true;
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply{IPC_SUCCESS};
 }
 
-IPCCommandResult Device::Close(u32 fd)
+std::optional<IPCReply> Device::Close(u32 fd)
 {
   m_is_active = false;
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply{IPC_SUCCESS};
 }
 
-IPCCommandResult Device::Unsupported(const Request& request)
+std::optional<IPCReply> Device::Unsupported(const Request& request)
 {
   static const std::map<IPCCommandType, std::string_view> names{{
       {IPC_CMD_READ, "Read"},
@@ -183,27 +183,6 @@ IPCCommandResult Device::Unsupported(const Request& request)
   }};
 
   WARN_LOG_FMT(IOS, "{} does not support {}()", m_name, names.at(request.command));
-  return GetDefaultReply(IPC_EINVAL);
-}
-
-// Returns an IPCCommandResult for a reply with an average reply time for devices
-// Please avoid using this function if more accurate timings are known.
-IPCCommandResult Device::GetDefaultReply(const s32 return_value)
-{
-  // Based on a hardware test, a device takes at least ~2700 ticks to reply to an IPC request.
-  // Depending on how much work a command performs, this can take much longer (10000+)
-  // especially if the NAND filesystem is accessed.
-  //
-  // Because we currently don't emulate timing very accurately, we should not return
-  // the minimum possible reply time (~960 ticks from the kernel or ~2700 from devices)
-  // but an average time, otherwise we are going to be much too fast in most cases.
-  return {return_value, true, 4000 * SystemTimers::TIMER_RATIO};
-}
-
-// Returns an IPCCommandResult with no reply. Useful for async commands that will generate a reply
-// later. This takes no return value because it won't be used.
-IPCCommandResult Device::GetNoReply()
-{
-  return {IPC_SUCCESS, false, 0};
+  return IPCReply{IPC_EINVAL};
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/Device.h b/Source/Core/Core/IOS/Device.h
index 13f5ea7803..91b0a150f9 100644
--- a/Source/Core/Core/IOS/Device.h
+++ b/Source/Core/Core/IOS/Device.h
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <cstddef>
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -186,19 +187,23 @@ public:
   const std::string& GetDeviceName() const { return m_name; }
   // Replies to Open and Close requests are sent by the IPC request handler (HandleCommand),
   // not by the devices themselves.
-  virtual IPCCommandResult Open(const OpenRequest& request);
-  virtual IPCCommandResult Close(u32 fd);
-  virtual IPCCommandResult Seek(const SeekRequest& seek) { return Unsupported(seek); }
-  virtual IPCCommandResult Read(const ReadWriteRequest& read) { return Unsupported(read); }
-  virtual IPCCommandResult Write(const ReadWriteRequest& write) { return Unsupported(write); }
-  virtual IPCCommandResult IOCtl(const IOCtlRequest& ioctl) { return Unsupported(ioctl); }
-  virtual IPCCommandResult IOCtlV(const IOCtlVRequest& ioctlv) { return Unsupported(ioctlv); }
+  virtual std::optional<IPCReply> Open(const OpenRequest& request);
+  virtual std::optional<IPCReply> Close(u32 fd);
+  virtual std::optional<IPCReply> Seek(const SeekRequest& seek) { return Unsupported(seek); }
+  virtual std::optional<IPCReply> Read(const ReadWriteRequest& read) { return Unsupported(read); }
+  virtual std::optional<IPCReply> Write(const ReadWriteRequest& write)
+  {
+    return Unsupported(write);
+  }
+  virtual std::optional<IPCReply> IOCtl(const IOCtlRequest& ioctl) { return Unsupported(ioctl); }
+  virtual std::optional<IPCReply> IOCtlV(const IOCtlVRequest& ioctlv)
+  {
+    return Unsupported(ioctlv);
+  }
   virtual void Update() {}
   virtual void UpdateWantDeterminism(bool new_want_determinism) {}
   virtual DeviceType GetDeviceType() const { return m_device_type; }
   virtual bool IsOpened() const { return m_is_active; }
-  static IPCCommandResult GetDefaultReply(s32 return_value);
-  static IPCCommandResult GetNoReply();
 
 protected:
   Kernel& m_ios;
@@ -209,6 +214,6 @@ protected:
   bool m_is_active = false;
 
 private:
-  IPCCommandResult Unsupported(const Request& request);
+  std::optional<IPCReply> Unsupported(const Request& request);
 };
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/DeviceStub.cpp b/Source/Core/Core/IOS/DeviceStub.cpp
index 8c197428ec..55f558aa7f 100644
--- a/Source/Core/Core/IOS/DeviceStub.cpp
+++ b/Source/Core/Core/IOS/DeviceStub.cpp
@@ -8,22 +8,22 @@
 
 namespace IOS::HLE
 {
-IPCCommandResult DeviceStub::Open(const OpenRequest& request)
+std::optional<IPCReply> DeviceStub::Open(const OpenRequest& request)
 {
   WARN_LOG_FMT(IOS, "{} faking Open()", m_name);
   m_is_active = true;
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult DeviceStub::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> DeviceStub::IOCtl(const IOCtlRequest& request)
 {
   WARN_LOG_FMT(IOS, "{} faking IOCtl()", m_name);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult DeviceStub::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> DeviceStub::IOCtlV(const IOCtlVRequest& request)
 {
   WARN_LOG_FMT(IOS, "{} faking IOCtlV()", m_name);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/DeviceStub.h b/Source/Core/Core/IOS/DeviceStub.h
index f344a8af87..c5f999c1a5 100644
--- a/Source/Core/Core/IOS/DeviceStub.h
+++ b/Source/Core/Core/IOS/DeviceStub.h
@@ -17,8 +17,8 @@ class DeviceStub final : public Device
 public:
   // Inherit the constructor from the Device class, since we don't need to do anything special.
   using Device::Device;
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 };
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/DolphinDevice.cpp b/Source/Core/Core/IOS/DolphinDevice.cpp
index 793ed85598..bcf75149c1 100644
--- a/Source/Core/Core/IOS/DolphinDevice.cpp
+++ b/Source/Core/Core/IOS/DolphinDevice.cpp
@@ -34,29 +34,29 @@ enum
 
 };
 
-IPCCommandResult GetSystemTime(const IOCtlVRequest& request)
+IPCReply GetSystemTime(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1))
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   if (request.io_vectors[0].size != 4)
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   const u32 milliseconds = Common::Timer::GetTimeMs();
 
   Memory::Write_U32(milliseconds, request.io_vectors[0].address);
-  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult GetVersion(const IOCtlVRequest& request)
+IPCReply GetVersion(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1))
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   const auto length = std::min(size_t(request.io_vectors[0].size), std::strlen(SCM_DESC_STR));
@@ -64,19 +64,19 @@ IPCCommandResult GetVersion(const IOCtlVRequest& request)
   Memory::Memset(request.io_vectors[0].address, 0, request.io_vectors[0].size);
   Memory::CopyToEmu(request.io_vectors[0].address, SCM_DESC_STR, length);
 
-  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult GetCPUSpeed(const IOCtlVRequest& request)
+IPCReply GetCPUSpeed(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1))
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   if (request.io_vectors[0].size != 4)
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   const SConfig& config = SConfig::GetInstance();
@@ -86,66 +86,66 @@ IPCCommandResult GetCPUSpeed(const IOCtlVRequest& request)
 
   Memory::Write_U32(core_clock, request.io_vectors[0].address);
 
-  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult GetSpeedLimit(const IOCtlVRequest& request)
+IPCReply GetSpeedLimit(const IOCtlVRequest& request)
 {
   // get current speed limit
   if (!request.HasNumberOfValidVectors(0, 1))
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   if (request.io_vectors[0].size != 4)
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   const SConfig& config = SConfig::GetInstance();
   const u32 speed_percent = config.m_EmulationSpeed * 100;
   Memory::Write_U32(speed_percent, request.io_vectors[0].address);
 
-  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SetSpeedLimit(const IOCtlVRequest& request)
+IPCReply SetSpeedLimit(const IOCtlVRequest& request)
 {
   // set current speed limit
   if (!request.HasNumberOfValidVectors(1, 0))
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   if (request.in_vectors[0].size != 4)
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   const float speed = float(Memory::Read_U32(request.in_vectors[0].address)) / 100.0f;
   SConfig::GetInstance().m_EmulationSpeed = speed;
   BootManager::SetEmulationSpeedReset(true);
 
-  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult GetRealProductCode(const IOCtlVRequest& request)
+IPCReply GetRealProductCode(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1))
   {
-    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   const std::string backup_file_path = File::GetUserPath(D_BACKUP_IDX) + DIR_SEP + WII_SETTING;
 
   File::IOFile file(backup_file_path, "rb");
   if (!file)
-    return DolphinDevice::GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
 
   Common::SettingsHandler::Buffer data;
 
   if (!file.ReadBytes(data.data(), data.size()))
-    return DolphinDevice::GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
 
   Common::SettingsHandler gen;
   gen.SetBytes(std::move(data));
@@ -153,21 +153,19 @@ IPCCommandResult GetRealProductCode(const IOCtlVRequest& request)
 
   const size_t length = std::min<size_t>(request.io_vectors[0].size, code.length());
   if (length == 0)
-    return DolphinDevice::GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
 
   Memory::Memset(request.io_vectors[0].address, 0, request.io_vectors[0].size);
   Memory::CopyToEmu(request.io_vectors[0].address, code.c_str(), length);
-  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 }  // namespace
 
-IPCCommandResult DolphinDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> DolphinDevice::IOCtlV(const IOCtlVRequest& request)
 {
   if (Core::WantsDeterminism())
-  {
-    return DolphinDevice::GetDefaultReply(IPC_EACCES);
-  }
+    return IPCReply(IPC_EACCES);
 
   switch (request.request)
   {
@@ -184,7 +182,7 @@ IPCCommandResult DolphinDevice::IOCtlV(const IOCtlVRequest& request)
   case IOCTL_DOLPHIN_GET_REAL_PRODUCTCODE:
     return GetRealProductCode(request);
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/DolphinDevice.h b/Source/Core/Core/IOS/DolphinDevice.h
index d3afbed20e..4d329b35e9 100644
--- a/Source/Core/Core/IOS/DolphinDevice.h
+++ b/Source/Core/Core/IOS/DolphinDevice.h
@@ -13,6 +13,6 @@ class DolphinDevice final : public Device
 public:
   // Inherit the constructor from the Device class, since we don't need to do anything special.
   using Device::Device;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 };
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/ES/ES.cpp b/Source/Core/Core/IOS/ES/ES.cpp
index 4ad07677f9..8be562c84b 100644
--- a/Source/Core/Core/IOS/ES/ES.cpp
+++ b/Source/Core/Core/IOS/ES/ES.cpp
@@ -120,10 +120,10 @@ void TitleContext::Update(const ES::TMDReader& tmd_, const ES::TicketReader& tic
   }
 }
 
-IPCCommandResult ESDevice::GetTitleDirectory(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTitleDirectory(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
 
@@ -132,7 +132,7 @@ IPCCommandResult ESDevice::GetTitleDirectory(const IOCtlVRequest& request)
           static_cast<u32>(title_id));
 
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_GETTITLEDIR: {}", path);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 ReturnCode ESDevice::GetTitleId(u64* title_id) const
@@ -143,20 +143,20 @@ ReturnCode ESDevice::GetTitleId(u64* title_id) const
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::GetTitleId(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTitleId(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u64 title_id;
   const ReturnCode ret = GetTitleId(&title_id);
   if (ret != IPC_SUCCESS)
-    return GetDefaultReply(ret);
+    return IPCReply(ret);
 
   Memory::Write_U64(title_id, request.io_vectors[0].address);
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_GETTITLEID: {:08x}/{:08x}", static_cast<u32>(title_id >> 32),
                static_cast<u32>(title_id));
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 static bool UpdateUIDAndGID(Kernel& kernel, const ES::TMDReader& tmd)
@@ -196,10 +196,10 @@ static ReturnCode CheckIsAllowedToSetUID(Kernel& kernel, const u32 caller_uid,
   return ES_EINVAL;
 }
 
-IPCCommandResult ESDevice::SetUID(u32 uid, const IOCtlVRequest& request)
+IPCReply ESDevice::SetUID(u32 uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != 8)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
 
@@ -207,20 +207,20 @@ IPCCommandResult ESDevice::SetUID(u32 uid, const IOCtlVRequest& request)
   if (ret < 0)
   {
     ERROR_LOG_FMT(IOS_ES, "SetUID: Permission check failed with error {}", ret);
-    return GetDefaultReply(ret);
+    return IPCReply(ret);
   }
 
   const auto tmd = FindInstalledTMD(title_id);
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
   if (!UpdateUIDAndGID(m_ios, tmd))
   {
     ERROR_LOG_FMT(IOS_ES, "SetUID: Failed to get UID for title {:016x}", title_id);
-    return GetDefaultReply(ES_SHORT_READ);
+    return IPCReply(ES_SHORT_READ);
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 bool ESDevice::LaunchTitle(u64 title_id, bool skip_reload)
@@ -380,11 +380,11 @@ ESDevice::ContextArray::iterator ESDevice::FindInactiveContext()
                       [](const auto& context) { return !context.active; });
 }
 
-IPCCommandResult ESDevice::Open(const OpenRequest& request)
+std::optional<IPCReply> ESDevice::Open(const OpenRequest& request)
 {
   auto context = FindInactiveContext();
   if (context == m_contexts.end())
-    return GetDefaultReply(ES_FD_EXHAUSTED);
+    return IPCReply{ES_FD_EXHAUSTED};
 
   context->active = true;
   context->uid = request.uid;
@@ -393,26 +393,26 @@ IPCCommandResult ESDevice::Open(const OpenRequest& request)
   return Device::Open(request);
 }
 
-IPCCommandResult ESDevice::Close(u32 fd)
+std::optional<IPCReply> ESDevice::Close(u32 fd)
 {
   auto context = FindActiveContext(fd);
   if (context == m_contexts.end())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   context->active = false;
   context->ipc_fd = -1;
 
   INFO_LOG_FMT(IOS_ES, "ES: Close");
   m_is_active = false;
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> ESDevice::IOCtlV(const IOCtlVRequest& request)
 {
   DEBUG_LOG_FMT(IOS_ES, "{} ({:#x})", GetDeviceName(), request.request);
   auto context = FindActiveContext(request.fd);
   if (context == m_contexts.end())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   switch (request.request)
   {
@@ -562,29 +562,29 @@ IPCCommandResult ESDevice::IOCtlV(const IOCtlVRequest& request)
     PanicAlertFmt("IOS-ES: Unimplemented ioctlv {:#x} ({} in vectors, {} io vectors)",
                   request.request, request.in_vectors.size(), request.io_vectors.size());
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_ES, Common::Log::LERROR);
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   case IOCTL_ES_INVALID_3F:
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 
-IPCCommandResult ESDevice::GetConsumption(const IOCtlVRequest& request)
+IPCReply ESDevice::GetConsumption(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 2))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   // This is at least what crediar's ES module does
   Memory::Write_U32(0, request.io_vectors[1].address);
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_GETCONSUMPTION");
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::Launch(const IOCtlVRequest& request)
+std::optional<IPCReply> ESDevice::Launch(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   const u32 view = Memory::Read_U32(request.in_vectors[1].address);
@@ -598,41 +598,41 @@ IPCCommandResult ESDevice::Launch(const IOCtlVRequest& request)
 
   // Prevent loading installed IOSes that are not emulated.
   if (!IsEmulated(title_id))
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
   // IOS replies to the request through the mailbox on failure, and acks if the launch succeeds.
   // Note: Launch will potentially reset the whole IOS state -- including this ES instance.
   if (!LaunchTitle(title_id))
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
   // ES_LAUNCH involves restarting IOS, which results in two acknowledgements in a row
   // (one from the previous IOS for this IPC request, and one from the new one as it boots).
   // Nothing should be written to the command buffer if the launch succeeded for obvious reasons.
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult ESDevice::LaunchBC(const IOCtlVRequest& request)
+std::optional<IPCReply> ESDevice::LaunchBC(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   // Here, IOS checks the clock speed and prevents ioctlv 0x25 from being used in GC mode.
   // An alternative way to do this is to check whether the current active IOS is MIOS.
   if (m_ios.GetVersion() == 0x101)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   if (!LaunchTitle(0x0000000100000100))
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
-  return GetNoReply();
+  return std::nullopt;
 }
 
 // This is technically an ioctlv in IOS's ES, but it is an internal API which cannot be
 // used from the PowerPC (for unpatched and up-to-date IOSes anyway).
 // So we block access to it from the IPC interface.
-IPCCommandResult ESDevice::DIVerify(const IOCtlVRequest& request)
+IPCReply ESDevice::DIVerify(const IOCtlVRequest& request)
 {
-  return GetDefaultReply(ES_EINVAL);
+  return IPCReply(ES_EINVAL);
 }
 
 static ReturnCode WriteTmdForDiVerify(FS::FileSystem* fs, const ES::TMDReader& tmd)
@@ -796,13 +796,13 @@ ReturnCode ESDevice::SetUpStreamKey(const u32 uid, const u8* ticket_view, const
                                          &ticket_bytes[offsetof(ES::Ticket, title_key)], PID_ES);
 }
 
-IPCCommandResult ESDevice::SetUpStreamKey(const Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::SetUpStreamKey(const Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1) ||
       request.in_vectors[0].size != sizeof(ES::TicketView) ||
       !ES::IsValidTMDSize(request.in_vectors[1].size) || request.io_vectors[0].size != sizeof(u32))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   std::vector<u8> tmd_bytes(request.in_vectors[1].size);
@@ -810,22 +810,22 @@ IPCCommandResult ESDevice::SetUpStreamKey(const Context& context, const IOCtlVRe
   const ES::TMDReader tmd{std::move(tmd_bytes)};
 
   if (!tmd.IsValid())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u32 handle;
   const ReturnCode ret =
       SetUpStreamKey(context.uid, Memory::GetPointer(request.in_vectors[0].address), tmd, &handle);
   Memory::Write_U32(handle, request.io_vectors[0].address);
-  return GetDefaultReply(ret);
+  return IPCReply(ret);
 }
 
-IPCCommandResult ESDevice::DeleteStreamKey(const IOCtlVRequest& request)
+IPCReply ESDevice::DeleteStreamKey(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 handle = Memory::Read_U32(request.in_vectors[0].address);
-  return GetDefaultReply(m_ios.GetIOSC().DeleteObject(handle, PID_ES));
+  return IPCReply(m_ios.GetIOSC().DeleteObject(handle, PID_ES));
 }
 
 bool ESDevice::IsActiveTitlePermittedByTicket(const u8* ticket_view) const
diff --git a/Source/Core/Core/IOS/ES/ES.h b/Source/Core/Core/IOS/ES/ES.h
index 9f521c29f0..c4636cab17 100644
--- a/Source/Core/Core/IOS/ES/ES.h
+++ b/Source/Core/Core/IOS/ES/ES.h
@@ -48,9 +48,9 @@ public:
 
   void DoState(PointerWrap& p) override;
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult Close(u32 fd) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Close(u32 fd) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   struct TitleImportExportContext
   {
@@ -261,84 +261,84 @@ private:
   using ContextArray = std::array<Context, 3>;
 
   // Title management
-  IPCCommandResult ImportTicket(const IOCtlVRequest& request);
-  IPCCommandResult ImportTmd(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ImportTitleInit(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ImportContentBegin(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ImportContentData(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ImportContentEnd(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ImportTitleDone(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ImportTitleCancel(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ExportTitleInit(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ExportContentBegin(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ExportContentData(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ExportContentEnd(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult ExportTitleDone(Context& context, const IOCtlVRequest& request);
-  IPCCommandResult DeleteTitle(const IOCtlVRequest& request);
-  IPCCommandResult DeleteTitleContent(const IOCtlVRequest& request);
-  IPCCommandResult DeleteTicket(const IOCtlVRequest& request);
-  IPCCommandResult DeleteSharedContent(const IOCtlVRequest& request);
-  IPCCommandResult DeleteContent(const IOCtlVRequest& request);
+  IPCReply ImportTicket(const IOCtlVRequest& request);
+  IPCReply ImportTmd(Context& context, const IOCtlVRequest& request);
+  IPCReply ImportTitleInit(Context& context, const IOCtlVRequest& request);
+  IPCReply ImportContentBegin(Context& context, const IOCtlVRequest& request);
+  IPCReply ImportContentData(Context& context, const IOCtlVRequest& request);
+  IPCReply ImportContentEnd(Context& context, const IOCtlVRequest& request);
+  IPCReply ImportTitleDone(Context& context, const IOCtlVRequest& request);
+  IPCReply ImportTitleCancel(Context& context, const IOCtlVRequest& request);
+  IPCReply ExportTitleInit(Context& context, const IOCtlVRequest& request);
+  IPCReply ExportContentBegin(Context& context, const IOCtlVRequest& request);
+  IPCReply ExportContentData(Context& context, const IOCtlVRequest& request);
+  IPCReply ExportContentEnd(Context& context, const IOCtlVRequest& request);
+  IPCReply ExportTitleDone(Context& context, const IOCtlVRequest& request);
+  IPCReply DeleteTitle(const IOCtlVRequest& request);
+  IPCReply DeleteTitleContent(const IOCtlVRequest& request);
+  IPCReply DeleteTicket(const IOCtlVRequest& request);
+  IPCReply DeleteSharedContent(const IOCtlVRequest& request);
+  IPCReply DeleteContent(const IOCtlVRequest& request);
 
   // Device identity and encryption
-  IPCCommandResult GetDeviceId(const IOCtlVRequest& request);
-  IPCCommandResult GetDeviceCertificate(const IOCtlVRequest& request);
-  IPCCommandResult CheckKoreaRegion(const IOCtlVRequest& request);
-  IPCCommandResult Sign(const IOCtlVRequest& request);
-  IPCCommandResult VerifySign(const IOCtlVRequest& request);
-  IPCCommandResult Encrypt(u32 uid, const IOCtlVRequest& request);
-  IPCCommandResult Decrypt(u32 uid, const IOCtlVRequest& request);
+  IPCReply GetDeviceId(const IOCtlVRequest& request);
+  IPCReply GetDeviceCertificate(const IOCtlVRequest& request);
+  IPCReply CheckKoreaRegion(const IOCtlVRequest& request);
+  IPCReply Sign(const IOCtlVRequest& request);
+  IPCReply VerifySign(const IOCtlVRequest& request);
+  IPCReply Encrypt(u32 uid, const IOCtlVRequest& request);
+  IPCReply Decrypt(u32 uid, const IOCtlVRequest& request);
 
   // Misc
-  IPCCommandResult SetUID(u32 uid, const IOCtlVRequest& request);
-  IPCCommandResult GetTitleDirectory(const IOCtlVRequest& request);
-  IPCCommandResult GetTitleId(const IOCtlVRequest& request);
-  IPCCommandResult GetConsumption(const IOCtlVRequest& request);
-  IPCCommandResult Launch(const IOCtlVRequest& request);
-  IPCCommandResult LaunchBC(const IOCtlVRequest& request);
-  IPCCommandResult DIVerify(const IOCtlVRequest& request);
-  IPCCommandResult SetUpStreamKey(const Context& context, const IOCtlVRequest& request);
-  IPCCommandResult DeleteStreamKey(const IOCtlVRequest& request);
+  IPCReply SetUID(u32 uid, const IOCtlVRequest& request);
+  IPCReply GetTitleDirectory(const IOCtlVRequest& request);
+  IPCReply GetTitleId(const IOCtlVRequest& request);
+  IPCReply GetConsumption(const IOCtlVRequest& request);
+  std::optional<IPCReply> Launch(const IOCtlVRequest& request);
+  std::optional<IPCReply> LaunchBC(const IOCtlVRequest& request);
+  IPCReply DIVerify(const IOCtlVRequest& request);
+  IPCReply SetUpStreamKey(const Context& context, const IOCtlVRequest& request);
+  IPCReply DeleteStreamKey(const IOCtlVRequest& request);
 
   // Title contents
-  IPCCommandResult OpenActiveTitleContent(u32 uid, const IOCtlVRequest& request);
-  IPCCommandResult OpenContent(u32 uid, const IOCtlVRequest& request);
-  IPCCommandResult ReadContent(u32 uid, const IOCtlVRequest& request);
-  IPCCommandResult CloseContent(u32 uid, const IOCtlVRequest& request);
-  IPCCommandResult SeekContent(u32 uid, const IOCtlVRequest& request);
+  IPCReply OpenActiveTitleContent(u32 uid, const IOCtlVRequest& request);
+  IPCReply OpenContent(u32 uid, const IOCtlVRequest& request);
+  IPCReply ReadContent(u32 uid, const IOCtlVRequest& request);
+  IPCReply CloseContent(u32 uid, const IOCtlVRequest& request);
+  IPCReply SeekContent(u32 uid, const IOCtlVRequest& request);
 
   // Title information
-  IPCCommandResult GetTitleCount(const std::vector<u64>& titles, const IOCtlVRequest& request);
-  IPCCommandResult GetTitles(const std::vector<u64>& titles, const IOCtlVRequest& request);
-  IPCCommandResult GetOwnedTitleCount(const IOCtlVRequest& request);
-  IPCCommandResult GetOwnedTitles(const IOCtlVRequest& request);
-  IPCCommandResult GetTitleCount(const IOCtlVRequest& request);
-  IPCCommandResult GetTitles(const IOCtlVRequest& request);
-  IPCCommandResult GetBoot2Version(const IOCtlVRequest& request);
-  IPCCommandResult GetStoredContentsCount(const ES::TMDReader& tmd, const IOCtlVRequest& request);
-  IPCCommandResult GetStoredContents(const ES::TMDReader& tmd, const IOCtlVRequest& request);
-  IPCCommandResult GetStoredContentsCount(const IOCtlVRequest& request);
-  IPCCommandResult GetStoredContents(const IOCtlVRequest& request);
-  IPCCommandResult GetTMDStoredContentsCount(const IOCtlVRequest& request);
-  IPCCommandResult GetTMDStoredContents(const IOCtlVRequest& request);
-  IPCCommandResult GetStoredTMDSize(const IOCtlVRequest& request);
-  IPCCommandResult GetStoredTMD(const IOCtlVRequest& request);
-  IPCCommandResult GetSharedContentsCount(const IOCtlVRequest& request) const;
-  IPCCommandResult GetSharedContents(const IOCtlVRequest& request) const;
+  IPCReply GetTitleCount(const std::vector<u64>& titles, const IOCtlVRequest& request);
+  IPCReply GetTitles(const std::vector<u64>& titles, const IOCtlVRequest& request);
+  IPCReply GetOwnedTitleCount(const IOCtlVRequest& request);
+  IPCReply GetOwnedTitles(const IOCtlVRequest& request);
+  IPCReply GetTitleCount(const IOCtlVRequest& request);
+  IPCReply GetTitles(const IOCtlVRequest& request);
+  IPCReply GetBoot2Version(const IOCtlVRequest& request);
+  IPCReply GetStoredContentsCount(const ES::TMDReader& tmd, const IOCtlVRequest& request);
+  IPCReply GetStoredContents(const ES::TMDReader& tmd, const IOCtlVRequest& request);
+  IPCReply GetStoredContentsCount(const IOCtlVRequest& request);
+  IPCReply GetStoredContents(const IOCtlVRequest& request);
+  IPCReply GetTMDStoredContentsCount(const IOCtlVRequest& request);
+  IPCReply GetTMDStoredContents(const IOCtlVRequest& request);
+  IPCReply GetStoredTMDSize(const IOCtlVRequest& request);
+  IPCReply GetStoredTMD(const IOCtlVRequest& request);
+  IPCReply GetSharedContentsCount(const IOCtlVRequest& request) const;
+  IPCReply GetSharedContents(const IOCtlVRequest& request) const;
 
   // Views for tickets and TMDs
-  IPCCommandResult GetTicketViewCount(const IOCtlVRequest& request);
-  IPCCommandResult GetTicketViews(const IOCtlVRequest& request);
-  IPCCommandResult GetV0TicketFromView(const IOCtlVRequest& request);
-  IPCCommandResult GetTicketSizeFromView(const IOCtlVRequest& request);
-  IPCCommandResult GetTicketFromView(const IOCtlVRequest& request);
-  IPCCommandResult GetTMDViewSize(const IOCtlVRequest& request);
-  IPCCommandResult GetTMDViews(const IOCtlVRequest& request);
-  IPCCommandResult DIGetTicketView(const IOCtlVRequest& request);
-  IPCCommandResult DIGetTMDViewSize(const IOCtlVRequest& request);
-  IPCCommandResult DIGetTMDView(const IOCtlVRequest& request);
-  IPCCommandResult DIGetTMDSize(const IOCtlVRequest& request);
-  IPCCommandResult DIGetTMD(const IOCtlVRequest& request);
+  IPCReply GetTicketViewCount(const IOCtlVRequest& request);
+  IPCReply GetTicketViews(const IOCtlVRequest& request);
+  IPCReply GetV0TicketFromView(const IOCtlVRequest& request);
+  IPCReply GetTicketSizeFromView(const IOCtlVRequest& request);
+  IPCReply GetTicketFromView(const IOCtlVRequest& request);
+  IPCReply GetTMDViewSize(const IOCtlVRequest& request);
+  IPCReply GetTMDViews(const IOCtlVRequest& request);
+  IPCReply DIGetTicketView(const IOCtlVRequest& request);
+  IPCReply DIGetTMDViewSize(const IOCtlVRequest& request);
+  IPCReply DIGetTMDView(const IOCtlVRequest& request);
+  IPCReply DIGetTMDSize(const IOCtlVRequest& request);
+  IPCReply DIGetTMD(const IOCtlVRequest& request);
 
   ContextArray::iterator FindActiveContext(s32 fd);
   ContextArray::iterator FindInactiveContext();
diff --git a/Source/Core/Core/IOS/ES/Identity.cpp b/Source/Core/Core/IOS/ES/Identity.cpp
index b61b90e189..3f5c4f6dab 100644
--- a/Source/Core/Core/IOS/ES/Identity.cpp
+++ b/Source/Core/Core/IOS/ES/Identity.cpp
@@ -27,23 +27,23 @@ ReturnCode ESDevice::GetDeviceId(u32* device_id) const
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::GetDeviceId(const IOCtlVRequest& request)
+IPCReply ESDevice::GetDeviceId(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1) || request.io_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u32 device_id;
   const ReturnCode ret = GetDeviceId(&device_id);
   if (ret != IPC_SUCCESS)
-    return GetDefaultReply(ret);
+    return IPCReply(ret);
   Memory::Write_U32(device_id, request.io_vectors[0].address);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::Encrypt(u32 uid, const IOCtlVRequest& request)
+IPCReply ESDevice::Encrypt(u32 uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(3, 2))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u32 keyIndex = Memory::Read_U32(request.in_vectors[0].address);
   u8* source = Memory::GetPointer(request.in_vectors[2].address);
@@ -54,13 +54,13 @@ IPCCommandResult ESDevice::Encrypt(u32 uid, const IOCtlVRequest& request)
   // TODO: Check whether the active title is allowed to encrypt.
 
   const ReturnCode ret = m_ios.GetIOSC().Encrypt(keyIndex, iv, source, size, destination, PID_ES);
-  return GetDefaultReply(ret);
+  return IPCReply(ret);
 }
 
-IPCCommandResult ESDevice::Decrypt(u32 uid, const IOCtlVRequest& request)
+IPCReply ESDevice::Decrypt(u32 uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(3, 2))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u32 keyIndex = Memory::Read_U32(request.in_vectors[0].address);
   u8* source = Memory::GetPointer(request.in_vectors[2].address);
@@ -71,38 +71,38 @@ IPCCommandResult ESDevice::Decrypt(u32 uid, const IOCtlVRequest& request)
   // TODO: Check whether the active title is allowed to decrypt.
 
   const ReturnCode ret = m_ios.GetIOSC().Decrypt(keyIndex, iv, source, size, destination, PID_ES);
-  return GetDefaultReply(ret);
+  return IPCReply(ret);
 }
 
-IPCCommandResult ESDevice::CheckKoreaRegion(const IOCtlVRequest& request)
+IPCReply ESDevice::CheckKoreaRegion(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   // note by DacoTaco : name is unknown, I just tried to name it SOMETHING.
   // IOS70 has this to let system menu 4.2 check if the console is region changed. it returns
   // -1017
   // if the IOS didn't find the Korean keys and 0 if it does. 0 leads to a error 003
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_CHECKKOREAREGION: Title checked for Korean keys.");
-  return GetDefaultReply(ES_EINVAL);
+  return IPCReply(ES_EINVAL);
 }
 
-IPCCommandResult ESDevice::GetDeviceCertificate(const IOCtlVRequest& request)
+IPCReply ESDevice::GetDeviceCertificate(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1) || request.io_vectors[0].size != 0x180)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_GETDEVICECERT");
 
   const IOS::CertECC cert = m_ios.GetIOSC().GetDeviceCertificate();
   Memory::CopyToEmu(request.io_vectors[0].address, &cert, sizeof(cert));
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::Sign(const IOCtlVRequest& request)
+IPCReply ESDevice::Sign(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 2))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_SIGN");
   u8* ap_cert_out = Memory::GetPointer(request.io_vectors[1].address);
@@ -111,10 +111,10 @@ IPCCommandResult ESDevice::Sign(const IOCtlVRequest& request)
   u8* sig_out = Memory::GetPointer(request.io_vectors[0].address);
 
   if (!m_title_context.active)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   m_ios.GetIOSC().Sign(sig_out, ap_cert_out, m_title_context.tmd.GetTitleId(), data, data_size);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 ReturnCode ESDevice::VerifySign(const std::vector<u8>& hash, const std::vector<u8>& ecc_signature,
@@ -185,12 +185,12 @@ ReturnCode ESDevice::VerifySign(const std::vector<u8>& hash, const std::vector<u
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::VerifySign(const IOCtlVRequest& request)
+IPCReply ESDevice::VerifySign(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(3, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   if (request.in_vectors[1].size != sizeof(Common::ec::Signature))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> hash(request.in_vectors[0].size);
   Memory::CopyFromEmu(hash.data(), request.in_vectors[0].address, hash.size());
@@ -201,6 +201,6 @@ IPCCommandResult ESDevice::VerifySign(const IOCtlVRequest& request)
   std::vector<u8> certs(request.in_vectors[2].size);
   Memory::CopyFromEmu(certs.data(), request.in_vectors[2].address, certs.size());
 
-  return GetDefaultReply(VerifySign(hash, ecc_signature, certs));
+  return IPCReply(VerifySign(hash, ecc_signature, certs));
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/ES/TitleContents.cpp b/Source/Core/Core/IOS/ES/TitleContents.cpp
index 8625ee9bc3..0cab7b7c91 100644
--- a/Source/Core/Core/IOS/ES/TitleContents.cpp
+++ b/Source/Core/Core/IOS/ES/TitleContents.cpp
@@ -46,13 +46,13 @@ s32 ESDevice::OpenContent(const ES::TMDReader& tmd, u16 content_index, u32 uid)
   return FS_EFDEXHAUSTED;
 }
 
-IPCCommandResult ESDevice::OpenContent(u32 uid, const IOCtlVRequest& request)
+IPCReply ESDevice::OpenContent(u32 uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(3, 0) || request.in_vectors[0].size != sizeof(u64) ||
       request.in_vectors[1].size != sizeof(ES::TicketView) ||
       request.in_vectors[2].size != sizeof(u32))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
@@ -61,27 +61,27 @@ IPCCommandResult ESDevice::OpenContent(u32 uid, const IOCtlVRequest& request)
 
   const auto tmd = FindInstalledTMD(title_id);
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
-  return GetDefaultReply(OpenContent(tmd, content_index, uid));
+  return IPCReply(OpenContent(tmd, content_index, uid));
 }
 
-IPCCommandResult ESDevice::OpenActiveTitleContent(u32 caller_uid, const IOCtlVRequest& request)
+IPCReply ESDevice::OpenActiveTitleContent(u32 caller_uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 content_index = Memory::Read_U32(request.in_vectors[0].address);
 
   if (!m_title_context.active)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   ES::UIDSys uid_map{m_ios.GetFS()};
   const u32 uid = uid_map.GetOrInsertUIDForTitle(m_title_context.tmd.GetTitleId());
   if (caller_uid != 0 && caller_uid != uid)
-    return GetDefaultReply(ES_EACCES);
+    return IPCReply(ES_EACCES);
 
-  return GetDefaultReply(OpenContent(m_title_context.tmd, content_index, caller_uid));
+  return IPCReply(OpenContent(m_title_context.tmd, content_index, caller_uid));
 }
 
 s32 ESDevice::ReadContent(u32 cfd, u8* buffer, u32 size, u32 uid)
@@ -99,16 +99,16 @@ s32 ESDevice::ReadContent(u32 cfd, u8* buffer, u32 size, u32 uid)
   return result.Succeeded() ? *result : FS::ConvertResult(result.Error());
 }
 
-IPCCommandResult ESDevice::ReadContent(u32 uid, const IOCtlVRequest& request)
+IPCReply ESDevice::ReadContent(u32 uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1) || request.in_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 cfd = Memory::Read_U32(request.in_vectors[0].address);
   const u32 size = request.io_vectors[0].size;
   const u32 addr = request.io_vectors[0].address;
 
-  return GetDefaultReply(ReadContent(cfd, Memory::GetPointer(addr), size, uid));
+  return IPCReply(ReadContent(cfd, Memory::GetPointer(addr), size, uid));
 }
 
 ReturnCode ESDevice::CloseContent(u32 cfd, u32 uid)
@@ -128,13 +128,13 @@ ReturnCode ESDevice::CloseContent(u32 cfd, u32 uid)
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::CloseContent(u32 uid, const IOCtlVRequest& request)
+IPCReply ESDevice::CloseContent(u32 uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 cfd = Memory::Read_U32(request.in_vectors[0].address);
-  return GetDefaultReply(CloseContent(cfd, uid));
+  return IPCReply(CloseContent(cfd, uid));
 }
 
 s32 ESDevice::SeekContent(u32 cfd, u32 offset, SeekMode mode, u32 uid)
@@ -152,15 +152,15 @@ s32 ESDevice::SeekContent(u32 cfd, u32 offset, SeekMode mode, u32 uid)
   return result.Succeeded() ? *result : FS::ConvertResult(result.Error());
 }
 
-IPCCommandResult ESDevice::SeekContent(u32 uid, const IOCtlVRequest& request)
+IPCReply ESDevice::SeekContent(u32 uid, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(3, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 cfd = Memory::Read_U32(request.in_vectors[0].address);
   const u32 offset = Memory::Read_U32(request.in_vectors[1].address);
   const SeekMode mode = static_cast<SeekMode>(Memory::Read_U32(request.in_vectors[2].address));
 
-  return GetDefaultReply(SeekContent(cfd, offset, mode, uid));
+  return IPCReply(SeekContent(cfd, offset, mode, uid));
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/ES/TitleInformation.cpp b/Source/Core/Core/IOS/ES/TitleInformation.cpp
index 4f1585ac55..3bd1427a8d 100644
--- a/Source/Core/Core/IOS/ES/TitleInformation.cpp
+++ b/Source/Core/Core/IOS/ES/TitleInformation.cpp
@@ -16,31 +16,30 @@ namespace IOS::HLE
 {
 // Used by the GetStoredContents ioctlvs. This assumes that the first output vector
 // is used for the content count (u32).
-IPCCommandResult ESDevice::GetStoredContentsCount(const ES::TMDReader& tmd,
-                                                  const IOCtlVRequest& request)
+IPCReply ESDevice::GetStoredContentsCount(const ES::TMDReader& tmd, const IOCtlVRequest& request)
 {
   if (request.io_vectors[0].size != sizeof(u32) || !tmd.IsValid())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u16 num_contents = static_cast<u16>(GetStoredContentsFromTMD(tmd).size());
   Memory::Write_U32(num_contents, request.io_vectors[0].address);
 
   INFO_LOG_FMT(IOS_ES, "GetStoredContentsCount ({:#x}):  {} content(s) for {:016x}",
                request.request, num_contents, tmd.GetTitleId());
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 // Used by the GetStoredContents ioctlvs. This assumes that the second input vector is used
 // for the content count and the output vector is used to store a list of content IDs (u32s).
-IPCCommandResult ESDevice::GetStoredContents(const ES::TMDReader& tmd, const IOCtlVRequest& request)
+IPCReply ESDevice::GetStoredContents(const ES::TMDReader& tmd, const IOCtlVRequest& request)
 {
   if (!tmd.IsValid())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   if (request.in_vectors[1].size != sizeof(u32) ||
       request.io_vectors[0].size != Memory::Read_U32(request.in_vectors[1].address) * sizeof(u32))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   const auto contents = GetStoredContentsFromTMD(tmd);
@@ -48,82 +47,81 @@ IPCCommandResult ESDevice::GetStoredContents(const ES::TMDReader& tmd, const IOC
   for (u32 i = 0; i < std::min(static_cast<u32>(contents.size()), max_content_count); ++i)
     Memory::Write_U32(contents[i].id, request.io_vectors[0].address + i * sizeof(u32));
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetStoredContentsCount(const IOCtlVRequest& request)
+IPCReply ESDevice::GetStoredContentsCount(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1) || request.in_vectors[0].size != sizeof(u64))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   const ES::TMDReader tmd = FindInstalledTMD(title_id);
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
   return GetStoredContentsCount(tmd, request);
 }
 
-IPCCommandResult ESDevice::GetStoredContents(const IOCtlVRequest& request)
+IPCReply ESDevice::GetStoredContents(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1) || request.in_vectors[0].size != sizeof(u64))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   const ES::TMDReader tmd = FindInstalledTMD(title_id);
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
   return GetStoredContents(tmd, request);
 }
 
-IPCCommandResult ESDevice::GetTMDStoredContentsCount(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTMDStoredContentsCount(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> tmd_bytes(request.in_vectors[0].size);
   Memory::CopyFromEmu(tmd_bytes.data(), request.in_vectors[0].address, tmd_bytes.size());
   return GetStoredContentsCount(ES::TMDReader{std::move(tmd_bytes)}, request);
 }
 
-IPCCommandResult ESDevice::GetTMDStoredContents(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTMDStoredContents(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> tmd_bytes(request.in_vectors[0].size);
   Memory::CopyFromEmu(tmd_bytes.data(), request.in_vectors[0].address, tmd_bytes.size());
 
   const ES::TMDReader tmd{std::move(tmd_bytes)};
   if (!tmd.IsValid())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> cert_store;
   ReturnCode ret = ReadCertStore(&cert_store);
   if (ret != IPC_SUCCESS)
-    return GetDefaultReply(ret);
+    return IPCReply(ret);
 
   ret = VerifyContainer(VerifyContainerType::TMD, VerifyMode::UpdateCertStore, tmd, cert_store);
   if (ret != IPC_SUCCESS)
-    return GetDefaultReply(ret);
+    return IPCReply(ret);
 
   return GetStoredContents(tmd, request);
 }
 
-IPCCommandResult ESDevice::GetTitleCount(const std::vector<u64>& titles,
-                                         const IOCtlVRequest& request)
+IPCReply ESDevice::GetTitleCount(const std::vector<u64>& titles, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1) || request.io_vectors[0].size != 4)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   Memory::Write_U32(static_cast<u32>(titles.size()), request.io_vectors[0].address);
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetTitles(const std::vector<u64>& titles, const IOCtlVRequest& request)
+IPCReply ESDevice::GetTitles(const std::vector<u64>& titles, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const size_t max_count = Memory::Read_U32(request.in_vectors[0].address);
   for (size_t i = 0; i < std::min(max_count, titles.size()); i++)
@@ -131,112 +129,112 @@ IPCCommandResult ESDevice::GetTitles(const std::vector<u64>& titles, const IOCtl
     Memory::Write_U64(titles[i], request.io_vectors[0].address + static_cast<u32>(i) * sizeof(u64));
     INFO_LOG_FMT(IOS_ES, "     title {:016x}", titles[i]);
   }
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetTitleCount(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTitleCount(const IOCtlVRequest& request)
 {
   const std::vector<u64> titles = GetInstalledTitles();
   INFO_LOG_FMT(IOS_ES, "GetTitleCount: {} titles", titles.size());
   return GetTitleCount(titles, request);
 }
 
-IPCCommandResult ESDevice::GetTitles(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTitles(const IOCtlVRequest& request)
 {
   return GetTitles(GetInstalledTitles(), request);
 }
 
-IPCCommandResult ESDevice::GetStoredTMDSize(const IOCtlVRequest& request)
+IPCReply ESDevice::GetStoredTMDSize(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   const ES::TMDReader tmd = FindInstalledTMD(title_id);
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
   const u32 tmd_size = static_cast<u32>(tmd.GetBytes().size());
   Memory::Write_U32(tmd_size, request.io_vectors[0].address);
 
   INFO_LOG_FMT(IOS_ES, "GetStoredTMDSize: {} bytes  for {:016x}", tmd_size, title_id);
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetStoredTMD(const IOCtlVRequest& request)
+IPCReply ESDevice::GetStoredTMD(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   const ES::TMDReader tmd = FindInstalledTMD(title_id);
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
   // TODO: actually use this param in when writing to the outbuffer :/
   const u32 MaxCount = Memory::Read_U32(request.in_vectors[1].address);
 
   const std::vector<u8>& raw_tmd = tmd.GetBytes();
   if (raw_tmd.size() != request.io_vectors[0].size)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   Memory::CopyToEmu(request.io_vectors[0].address, raw_tmd.data(), raw_tmd.size());
 
   INFO_LOG_FMT(IOS_ES, "GetStoredTMD: title {:016x} (buffer size: {})", title_id, MaxCount);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetOwnedTitleCount(const IOCtlVRequest& request)
+IPCReply ESDevice::GetOwnedTitleCount(const IOCtlVRequest& request)
 {
   const std::vector<u64> titles = GetTitlesWithTickets();
   INFO_LOG_FMT(IOS_ES, "GetOwnedTitleCount: {} titles", titles.size());
   return GetTitleCount(titles, request);
 }
 
-IPCCommandResult ESDevice::GetOwnedTitles(const IOCtlVRequest& request)
+IPCReply ESDevice::GetOwnedTitles(const IOCtlVRequest& request)
 {
   return GetTitles(GetTitlesWithTickets(), request);
 }
 
-IPCCommandResult ESDevice::GetBoot2Version(const IOCtlVRequest& request)
+IPCReply ESDevice::GetBoot2Version(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_GETBOOT2VERSION");
 
   // as of 26/02/2012, this was latest bootmii version
   Memory::Write_U32(4, request.io_vectors[0].address);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetSharedContentsCount(const IOCtlVRequest& request) const
+IPCReply ESDevice::GetSharedContentsCount(const IOCtlVRequest& request) const
 {
   if (!request.HasNumberOfValidVectors(0, 1) || request.io_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 count = GetSharedContentsCount();
   Memory::Write_U32(count, request.io_vectors[0].address);
 
   INFO_LOG_FMT(IOS_ES, "GetSharedContentsCount: {} contents", count);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetSharedContents(const IOCtlVRequest& request) const
+IPCReply ESDevice::GetSharedContents(const IOCtlVRequest& request) const
 {
   if (!request.HasNumberOfValidVectors(1, 1) || request.in_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 max_count = Memory::Read_U32(request.in_vectors[0].address);
   if (request.io_vectors[0].size != 20 * max_count)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const std::vector<std::array<u8, 20>> hashes = GetSharedContents();
   const u32 count = std::min(static_cast<u32>(hashes.size()), max_count);
   Memory::CopyToEmu(request.io_vectors[0].address, hashes.data(), 20 * count);
 
   INFO_LOG_FMT(IOS_ES, "GetSharedContents: {} contents ({} requested)", count, max_count);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/ES/TitleManagement.cpp b/Source/Core/Core/IOS/ES/TitleManagement.cpp
index cff3b42e34..09b543f1db 100644
--- a/Source/Core/Core/IOS/ES/TitleManagement.cpp
+++ b/Source/Core/Core/IOS/ES/TitleManagement.cpp
@@ -93,16 +93,16 @@ ReturnCode ESDevice::ImportTicket(const std::vector<u8>& ticket_bytes,
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ImportTicket(const IOCtlVRequest& request)
+IPCReply ESDevice::ImportTicket(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(3, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> bytes(request.in_vectors[0].size);
   Memory::CopyFromEmu(bytes.data(), request.in_vectors[0].address, request.in_vectors[0].size);
   std::vector<u8> cert_chain(request.in_vectors[1].size);
   Memory::CopyFromEmu(cert_chain.data(), request.in_vectors[1].address, request.in_vectors[1].size);
-  return GetDefaultReply(ImportTicket(bytes, cert_chain));
+  return IPCReply(ImportTicket(bytes, cert_chain));
 }
 
 constexpr std::array<u8, 16> NULL_KEY{};
@@ -180,18 +180,18 @@ ReturnCode ESDevice::ImportTmd(Context& context, const std::vector<u8>& tmd_byte
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ImportTmd(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ImportTmd(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   if (!ES::IsValidTMDSize(request.in_vectors[0].size))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> tmd(request.in_vectors[0].size);
   Memory::CopyFromEmu(tmd.data(), request.in_vectors[0].address, request.in_vectors[0].size);
-  return GetDefaultReply(ImportTmd(context, tmd, m_title_context.tmd.GetTitleId(),
-                                   m_title_context.tmd.GetTitleFlags()));
+  return IPCReply(ImportTmd(context, tmd, m_title_context.tmd.GetTitleId(),
+                            m_title_context.tmd.GetTitleFlags()));
 }
 
 static ReturnCode InitTitleImportKey(const std::vector<u8>& ticket_bytes, IOSC& iosc,
@@ -266,19 +266,19 @@ ReturnCode ESDevice::ImportTitleInit(Context& context, const std::vector<u8>& tm
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ImportTitleInit(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ImportTitleInit(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(4, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   if (!ES::IsValidTMDSize(request.in_vectors[0].size))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> tmd(request.in_vectors[0].size);
   Memory::CopyFromEmu(tmd.data(), request.in_vectors[0].address, request.in_vectors[0].size);
   std::vector<u8> certs(request.in_vectors[1].size);
   Memory::CopyFromEmu(certs.data(), request.in_vectors[1].address, request.in_vectors[1].size);
-  return GetDefaultReply(ImportTitleInit(context, tmd, certs));
+  return IPCReply(ImportTitleInit(context, tmd, certs));
 }
 
 ReturnCode ESDevice::ImportContentBegin(Context& context, u64 title_id, u32 content_id)
@@ -324,14 +324,14 @@ ReturnCode ESDevice::ImportContentBegin(Context& context, u64 title_id, u32 cont
   return static_cast<ReturnCode>(content_fd);
 }
 
-IPCCommandResult ESDevice::ImportContentBegin(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ImportContentBegin(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   u32 content_id = Memory::Read_U32(request.in_vectors[1].address);
-  return GetDefaultReply(ImportContentBegin(context, title_id, content_id));
+  return IPCReply(ImportContentBegin(context, title_id, content_id));
 }
 
 ReturnCode ESDevice::ImportContentData(Context& context, u32 content_fd, const u8* data,
@@ -343,15 +343,14 @@ ReturnCode ESDevice::ImportContentData(Context& context, u32 content_fd, const u
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ImportContentData(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ImportContentData(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u32 content_fd = Memory::Read_U32(request.in_vectors[0].address);
   u8* data_start = Memory::GetPointer(request.in_vectors[1].address);
-  return GetDefaultReply(
-      ImportContentData(context, content_fd, data_start, request.in_vectors[1].size));
+  return IPCReply(ImportContentData(context, content_fd, data_start, request.in_vectors[1].size));
 }
 
 static bool CheckIfContentHashMatches(const std::vector<u8>& content, const ES::Content& info)
@@ -429,13 +428,13 @@ ReturnCode ESDevice::ImportContentEnd(Context& context, u32 content_fd)
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ImportContentEnd(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ImportContentEnd(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   u32 content_fd = Memory::Read_U32(request.in_vectors[0].address);
-  return GetDefaultReply(ImportContentEnd(context, content_fd));
+  return IPCReply(ImportContentEnd(context, content_fd));
 }
 
 static bool HasAllRequiredContents(Kernel& ios, const ES::TMDReader& tmd)
@@ -492,12 +491,12 @@ ReturnCode ESDevice::ImportTitleDone(Context& context)
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ImportTitleDone(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ImportTitleDone(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
-  return GetDefaultReply(ImportTitleDone(context));
+  return IPCReply(ImportTitleDone(context));
 }
 
 ReturnCode ESDevice::ImportTitleCancel(Context& context)
@@ -518,12 +517,12 @@ ReturnCode ESDevice::ImportTitleCancel(Context& context)
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ImportTitleCancel(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ImportTitleCancel(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 0))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
-  return GetDefaultReply(ImportTitleCancel(context));
+  return IPCReply(ImportTitleCancel(context));
 }
 
 static bool CanDeleteTitle(u64 title_id)
@@ -541,13 +540,13 @@ ReturnCode ESDevice::DeleteTitle(u64 title_id)
   return FS::ConvertResult(m_ios.GetFS()->Delete(PID_KERNEL, PID_KERNEL, title_dir));
 }
 
-IPCCommandResult ESDevice::DeleteTitle(const IOCtlVRequest& request)
+IPCReply ESDevice::DeleteTitle(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != 8)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
-  return GetDefaultReply(DeleteTitle(title_id));
+  return IPCReply(DeleteTitle(title_id));
 }
 
 ReturnCode ESDevice::DeleteTicket(const u8* ticket_view)
@@ -590,14 +589,14 @@ ReturnCode ESDevice::DeleteTicket(const u8* ticket_view)
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::DeleteTicket(const IOCtlVRequest& request)
+IPCReply ESDevice::DeleteTicket(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) ||
       request.in_vectors[0].size != sizeof(ES::TicketView))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
-  return GetDefaultReply(DeleteTicket(Memory::GetPointer(request.in_vectors[0].address)));
+  return IPCReply(DeleteTicket(Memory::GetPointer(request.in_vectors[0].address)));
 }
 
 ReturnCode ESDevice::DeleteTitleContent(u64 title_id) const
@@ -619,11 +618,11 @@ ReturnCode ESDevice::DeleteTitleContent(u64 title_id) const
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::DeleteTitleContent(const IOCtlVRequest& request)
+IPCReply ESDevice::DeleteTitleContent(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != sizeof(u64))
-    return GetDefaultReply(ES_EINVAL);
-  return GetDefaultReply(DeleteTitleContent(Memory::Read_U64(request.in_vectors[0].address)));
+    return IPCReply(ES_EINVAL);
+  return IPCReply(DeleteTitleContent(Memory::Read_U64(request.in_vectors[0].address)));
 }
 
 ReturnCode ESDevice::DeleteContent(u64 title_id, u32 content_id) const
@@ -644,15 +643,15 @@ ReturnCode ESDevice::DeleteContent(u64 title_id, u32 content_id) const
   return FS::ConvertResult(m_ios.GetFS()->Delete(PID_KERNEL, PID_KERNEL, path));
 }
 
-IPCCommandResult ESDevice::DeleteContent(const IOCtlVRequest& request)
+IPCReply ESDevice::DeleteContent(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 0) || request.in_vectors[0].size != sizeof(u64) ||
       request.in_vectors[1].size != sizeof(u32))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
-  return GetDefaultReply(DeleteContent(Memory::Read_U64(request.in_vectors[0].address),
-                                       Memory::Read_U32(request.in_vectors[1].address)));
+  return IPCReply(DeleteContent(Memory::Read_U64(request.in_vectors[0].address),
+                                Memory::Read_U32(request.in_vectors[1].address)));
 }
 
 ReturnCode ESDevice::ExportTitleInit(Context& context, u64 title_id, u8* tmd_bytes, u32 tmd_size,
@@ -684,18 +683,18 @@ ReturnCode ESDevice::ExportTitleInit(Context& context, u64 title_id, u8* tmd_byt
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ExportTitleInit(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ExportTitleInit(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1) || request.in_vectors[0].size != 8)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   u8* tmd_bytes = Memory::GetPointer(request.io_vectors[0].address);
   const u32 tmd_size = request.io_vectors[0].size;
 
-  return GetDefaultReply(ExportTitleInit(context, title_id, tmd_bytes, tmd_size,
-                                         m_title_context.tmd.GetTitleId(),
-                                         m_title_context.tmd.GetTitleFlags()));
+  return IPCReply(ExportTitleInit(context, title_id, tmd_bytes, tmd_size,
+                                  m_title_context.tmd.GetTitleId(),
+                                  m_title_context.tmd.GetTitleFlags()));
 }
 
 ReturnCode ESDevice::ExportContentBegin(Context& context, u64 title_id, u32 content_id)
@@ -729,16 +728,16 @@ ReturnCode ESDevice::ExportContentBegin(Context& context, u64 title_id, u32 cont
   return static_cast<ReturnCode>(ret);
 }
 
-IPCCommandResult ESDevice::ExportContentBegin(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ExportContentBegin(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 0) || request.in_vectors[0].size != 8 ||
       request.in_vectors[1].size != 4)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   const u32 content_id = Memory::Read_U32(request.in_vectors[1].address);
 
-  return GetDefaultReply(ExportContentBegin(context, title_id, content_id));
+  return IPCReply(ExportContentBegin(context, title_id, content_id));
 }
 
 ReturnCode ESDevice::ExportContentData(Context& context, u32 content_fd, u8* data, u32 data_size)
@@ -775,19 +774,19 @@ ReturnCode ESDevice::ExportContentData(Context& context, u32 content_fd, u8* dat
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ExportContentData(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ExportContentData(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1) || request.in_vectors[0].size != 4 ||
       request.io_vectors[0].size == 0)
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   const u32 content_fd = Memory::Read_U32(request.in_vectors[0].address);
   u8* data = Memory::GetPointer(request.io_vectors[0].address);
   const u32 bytes_to_read = request.io_vectors[0].size;
 
-  return GetDefaultReply(ExportContentData(context, content_fd, data, bytes_to_read));
+  return IPCReply(ExportContentData(context, content_fd, data, bytes_to_read));
 }
 
 ReturnCode ESDevice::ExportContentEnd(Context& context, u32 content_fd)
@@ -797,13 +796,13 @@ ReturnCode ESDevice::ExportContentEnd(Context& context, u32 content_fd)
   return CloseContent(content_fd, 0);
 }
 
-IPCCommandResult ESDevice::ExportContentEnd(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ExportContentEnd(Context& context, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != 4)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 content_fd = Memory::Read_U32(request.in_vectors[0].address);
-  return GetDefaultReply(ExportContentEnd(context, content_fd));
+  return IPCReply(ExportContentEnd(context, content_fd));
 }
 
 ReturnCode ESDevice::ExportTitleDone(Context& context)
@@ -812,9 +811,9 @@ ReturnCode ESDevice::ExportTitleDone(Context& context)
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::ExportTitleDone(Context& context, const IOCtlVRequest& request)
+IPCReply ESDevice::ExportTitleDone(Context& context, const IOCtlVRequest& request)
 {
-  return GetDefaultReply(ExportTitleDone(context));
+  return IPCReply(ExportTitleDone(context));
 }
 
 ReturnCode ESDevice::DeleteSharedContent(const std::array<u8, 20>& sha1) const
@@ -854,12 +853,12 @@ ReturnCode ESDevice::DeleteSharedContent(const std::array<u8, 20>& sha1) const
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::DeleteSharedContent(const IOCtlVRequest& request)
+IPCReply ESDevice::DeleteSharedContent(const IOCtlVRequest& request)
 {
   std::array<u8, 20> sha1;
   if (!request.HasNumberOfValidVectors(1, 0) || request.in_vectors[0].size != sha1.size())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   Memory::CopyFromEmu(sha1.data(), request.in_vectors[0].address, request.in_vectors[0].size);
-  return GetDefaultReply(DeleteSharedContent(sha1));
+  return IPCReply(DeleteSharedContent(sha1));
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/ES/Views.cpp b/Source/Core/Core/IOS/ES/Views.cpp
index 79c4d7f502..500445fd34 100644
--- a/Source/Core/Core/IOS/ES/Views.cpp
+++ b/Source/Core/Core/IOS/ES/Views.cpp
@@ -36,10 +36,10 @@ static bool ShouldReturnFakeViewsForIOSes(u64 title_id, const TitleContext& cont
          (ios && SConfig::GetInstance().m_disc_booted_from_game_list && disc_title);
 }
 
-IPCCommandResult ESDevice::GetTicketViewCount(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTicketViewCount(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 TitleID = Memory::Read_U64(request.in_vectors[0].address);
 
@@ -61,13 +61,13 @@ IPCCommandResult ESDevice::GetTicketViewCount(const IOCtlVRequest& request)
                view_count);
 
   Memory::Write_U32(view_count, request.io_vectors[0].address);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetTicketViews(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTicketViews(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 TitleID = Memory::Read_U64(request.in_vectors[0].address);
   const u32 maxViews = Memory::Read_U32(request.in_vectors[1].address);
@@ -96,7 +96,7 @@ IPCCommandResult ESDevice::GetTicketViews(const IOCtlVRequest& request)
 
   INFO_LOG_FMT(IOS_ES, "IOCTL_ES_GETVIEWS for titleID: {:016x} (MaxViews = {})", TitleID, maxViews);
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 ReturnCode ESDevice::GetV0TicketFromView(const u8* ticket_view, u8* ticket) const
@@ -157,106 +157,106 @@ ReturnCode ESDevice::GetTicketFromView(const u8* ticket_view, u8* ticket, u32* t
   return IPC_SUCCESS;
 }
 
-IPCCommandResult ESDevice::GetV0TicketFromView(const IOCtlVRequest& request)
+IPCReply ESDevice::GetV0TicketFromView(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1) ||
       request.in_vectors[0].size != sizeof(ES::TicketView) ||
       request.io_vectors[0].size != sizeof(ES::Ticket))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
-  return GetDefaultReply(GetV0TicketFromView(Memory::GetPointer(request.in_vectors[0].address),
-                                             Memory::GetPointer(request.io_vectors[0].address)));
+  return IPCReply(GetV0TicketFromView(Memory::GetPointer(request.in_vectors[0].address),
+                                      Memory::GetPointer(request.io_vectors[0].address)));
 }
 
-IPCCommandResult ESDevice::GetTicketSizeFromView(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTicketSizeFromView(const IOCtlVRequest& request)
 {
   u32 ticket_size = 0;
   if (!request.HasNumberOfValidVectors(1, 1) ||
       request.in_vectors[0].size != sizeof(ES::TicketView) ||
       request.io_vectors[0].size != sizeof(ticket_size))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
   const ReturnCode ret =
       GetTicketFromView(Memory::GetPointer(request.in_vectors[0].address), nullptr, &ticket_size);
   Memory::Write_U32(ticket_size, request.io_vectors[0].address);
-  return GetDefaultReply(ret);
+  return IPCReply(ret);
 }
 
-IPCCommandResult ESDevice::GetTicketFromView(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTicketFromView(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1) ||
       request.in_vectors[0].size != sizeof(ES::TicketView) ||
       request.in_vectors[1].size != sizeof(u32))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   u32 ticket_size = Memory::Read_U32(request.in_vectors[1].address);
   if (ticket_size != request.io_vectors[0].size)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
-  return GetDefaultReply(GetTicketFromView(Memory::GetPointer(request.in_vectors[0].address),
-                                           Memory::GetPointer(request.io_vectors[0].address),
-                                           &ticket_size));
+  return IPCReply(GetTicketFromView(Memory::GetPointer(request.in_vectors[0].address),
+                                    Memory::GetPointer(request.io_vectors[0].address),
+                                    &ticket_size));
 }
 
-IPCCommandResult ESDevice::GetTMDViewSize(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTMDViewSize(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u64 TitleID = Memory::Read_U64(request.in_vectors[0].address);
   const ES::TMDReader tmd = FindInstalledTMD(TitleID);
 
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
   const u32 view_size = static_cast<u32>(tmd.GetRawView().size());
   Memory::Write_U32(view_size, request.io_vectors[0].address);
 
   INFO_LOG_FMT(IOS_ES, "GetTMDViewSize: {} bytes for title {:016x}", view_size, TitleID);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::GetTMDViews(const IOCtlVRequest& request)
+IPCReply ESDevice::GetTMDViews(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1) ||
       request.in_vectors[0].size != sizeof(ES::TMDHeader::title_id) ||
       request.in_vectors[1].size != sizeof(u32) ||
       Memory::Read_U32(request.in_vectors[1].address) != request.io_vectors[0].size)
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   const u64 title_id = Memory::Read_U64(request.in_vectors[0].address);
   const ES::TMDReader tmd = FindInstalledTMD(title_id);
 
   if (!tmd.IsValid())
-    return GetDefaultReply(FS_ENOENT);
+    return IPCReply(FS_ENOENT);
 
   const std::vector<u8> raw_view = tmd.GetRawView();
   if (request.io_vectors[0].size < raw_view.size())
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   Memory::CopyToEmu(request.io_vectors[0].address, raw_view.data(), raw_view.size());
 
   INFO_LOG_FMT(IOS_ES, "GetTMDView: {} bytes for title {:016x}", raw_view.size(), title_id);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::DIGetTMDViewSize(const IOCtlVRequest& request)
+IPCReply ESDevice::DIGetTMDViewSize(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   // Sanity check the TMD size.
   if (request.in_vectors[0].size >= 4 * 1024 * 1024)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   if (request.io_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const bool has_tmd = request.in_vectors[0].size != 0;
   size_t tmd_view_size = 0;
@@ -270,7 +270,7 @@ IPCCommandResult ESDevice::DIGetTMDViewSize(const IOCtlVRequest& request)
     // Yes, this returns -1017, not ES_INVALID_TMD.
     // IOS simply checks whether the TMD has all required content entries.
     if (!tmd.IsValid())
-      return GetDefaultReply(ES_EINVAL);
+      return IPCReply(ES_EINVAL);
 
     tmd_view_size = tmd.GetRawView().size();
   }
@@ -278,29 +278,29 @@ IPCCommandResult ESDevice::DIGetTMDViewSize(const IOCtlVRequest& request)
   {
     // If no TMD was passed in and no title is active, IOS returns -1017.
     if (!m_title_context.active)
-      return GetDefaultReply(ES_EINVAL);
+      return IPCReply(ES_EINVAL);
 
     tmd_view_size = m_title_context.tmd.GetRawView().size();
   }
 
   Memory::Write_U32(static_cast<u32>(tmd_view_size), request.io_vectors[0].address);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::DIGetTMDView(const IOCtlVRequest& request)
+IPCReply ESDevice::DIGetTMDView(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 1))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   // Sanity check the TMD size.
   if (request.in_vectors[0].size >= 4 * 1024 * 1024)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   // Check whether the TMD view size is consistent.
   if (request.in_vectors[1].size != sizeof(u32) ||
       Memory::Read_U32(request.in_vectors[1].address) != request.io_vectors[0].size)
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   const bool has_tmd = request.in_vectors[0].size != 0;
@@ -313,7 +313,7 @@ IPCCommandResult ESDevice::DIGetTMDView(const IOCtlVRequest& request)
     const ES::TMDReader tmd{std::move(tmd_bytes)};
 
     if (!tmd.IsValid())
-      return GetDefaultReply(ES_EINVAL);
+      return IPCReply(ES_EINVAL);
 
     tmd_view = tmd.GetRawView();
   }
@@ -321,31 +321,31 @@ IPCCommandResult ESDevice::DIGetTMDView(const IOCtlVRequest& request)
   {
     // If no TMD was passed in and no title is active, IOS returns -1017.
     if (!m_title_context.active)
-      return GetDefaultReply(ES_EINVAL);
+      return IPCReply(ES_EINVAL);
 
     tmd_view = m_title_context.tmd.GetRawView();
   }
 
   if (tmd_view.size() > request.io_vectors[0].size)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   Memory::CopyToEmu(request.io_vectors[0].address, tmd_view.data(), tmd_view.size());
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::DIGetTicketView(const IOCtlVRequest& request)
+IPCReply ESDevice::DIGetTicketView(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1) ||
       request.io_vectors[0].size != sizeof(ES::TicketView))
   {
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
   }
 
   const bool has_ticket_vector = request.in_vectors[0].size == sizeof(ES::Ticket);
 
   // This ioctlv takes either a signed ticket or no ticket, in which case the ticket size must be 0.
   if (!has_ticket_vector && request.in_vectors[0].size != 0)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   std::vector<u8> view;
 
@@ -354,7 +354,7 @@ IPCCommandResult ESDevice::DIGetTicketView(const IOCtlVRequest& request)
   if (!has_ticket_vector)
   {
     if (!m_title_context.active)
-      return GetDefaultReply(ES_EINVAL);
+      return IPCReply(ES_EINVAL);
 
     view = m_title_context.ticket.GetRawTicketView(0);
   }
@@ -368,40 +368,40 @@ IPCCommandResult ESDevice::DIGetTicketView(const IOCtlVRequest& request)
   }
 
   Memory::CopyToEmu(request.io_vectors[0].address, view.data(), view.size());
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::DIGetTMDSize(const IOCtlVRequest& request)
+IPCReply ESDevice::DIGetTMDSize(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(0, 1) || request.io_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   if (!m_title_context.active)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   Memory::Write_U32(static_cast<u32>(m_title_context.tmd.GetBytes().size()),
                     request.io_vectors[0].address);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult ESDevice::DIGetTMD(const IOCtlVRequest& request)
+IPCReply ESDevice::DIGetTMD(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1) || request.in_vectors[0].size != sizeof(u32))
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const u32 tmd_size = Memory::Read_U32(request.in_vectors[0].address);
   if (tmd_size != request.io_vectors[0].size)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   if (!m_title_context.active)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   const std::vector<u8>& tmd_bytes = m_title_context.tmd.GetBytes();
 
   if (static_cast<u32>(tmd_bytes.size()) > tmd_size)
-    return GetDefaultReply(ES_EINVAL);
+    return IPCReply(ES_EINVAL);
 
   Memory::CopyToEmu(request.io_vectors[0].address, tmd_bytes.data(), tmd_bytes.size());
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/FS/FileSystemProxy.cpp b/Source/Core/Core/IOS/FS/FileSystemProxy.cpp
index 10cc687355..26e1ce424f 100644
--- a/Source/Core/Core/IOS/FS/FileSystemProxy.cpp
+++ b/Source/Core/Core/IOS/FS/FileSystemProxy.cpp
@@ -22,10 +22,10 @@ namespace IOS::HLE
 {
 using namespace IOS::HLE::FS;
 
-static IPCCommandResult GetFSReply(s32 return_value, u64 extra_tb_ticks = 0)
+static IPCReply GetFSReply(s32 return_value, u64 extra_tb_ticks = 0)
 {
   // According to hardware tests, FS takes at least 2700 TB ticks to reply to commands.
-  return {return_value, true, (2700 + extra_tb_ticks) * SystemTimers::TIMER_RATIO};
+  return IPCReply{return_value, (2700 + extra_tb_ticks) * SystemTimers::TIMER_RATIO};
 }
 
 /// Amount of TB ticks required for a superblock write to complete.
@@ -97,13 +97,13 @@ static u64 EstimateFileLookupTicks(const std::string& path, FileLookupMode mode)
 ///
 /// A superblock flush takes a very large amount of time, so other delays are ignored
 /// to simplify the implementation as they are insignificant.
-static IPCCommandResult GetReplyForSuperblockOperation(ResultCode result)
+static IPCReply GetReplyForSuperblockOperation(ResultCode result)
 {
   const u64 ticks = result == ResultCode::Success ? SUPERBLOCK_WRITE_TICKS : 0;
   return GetFSReply(ConvertResult(result), ticks);
 }
 
-IPCCommandResult FSDevice::Open(const OpenRequest& request)
+std::optional<IPCReply> FSDevice::Open(const OpenRequest& request)
 {
   if (m_fd_map.size() >= 16)
     return GetFSReply(ConvertResult(ResultCode::NoFreeHandle));
@@ -130,7 +130,7 @@ IPCCommandResult FSDevice::Open(const OpenRequest& request)
   return GetFSReply(IPC_SUCCESS, ticks);
 }
 
-IPCCommandResult FSDevice::Close(u32 fd)
+std::optional<IPCReply> FSDevice::Close(u32 fd)
 {
   u64 ticks = 0;
   if (m_fd_map[fd].fs_fd != INVALID_FD)
@@ -229,7 +229,7 @@ bool FSDevice::HasCacheForFile(u32 fd, u32 offset) const
   return m_cache_fd == fd && m_cache_chain_index == chain_index;
 }
 
-IPCCommandResult FSDevice::Read(const ReadWriteRequest& request)
+std::optional<IPCReply> FSDevice::Read(const ReadWriteRequest& request)
 {
   const Handle& handle = m_fd_map[request.fd];
   if (handle.fs_fd == INVALID_FD)
@@ -247,7 +247,7 @@ IPCCommandResult FSDevice::Read(const ReadWriteRequest& request)
   return GetFSReply(*result, ticks);
 }
 
-IPCCommandResult FSDevice::Write(const ReadWriteRequest& request)
+std::optional<IPCReply> FSDevice::Write(const ReadWriteRequest& request)
 {
   const Handle& handle = m_fd_map[request.fd];
   if (handle.fs_fd == INVALID_FD)
@@ -265,7 +265,7 @@ IPCCommandResult FSDevice::Write(const ReadWriteRequest& request)
   return GetFSReply(*result, ticks);
 }
 
-IPCCommandResult FSDevice::Seek(const SeekRequest& request)
+std::optional<IPCReply> FSDevice::Seek(const SeekRequest& request)
 {
   const Handle& handle = m_fd_map[request.fd];
   if (handle.fs_fd == INVALID_FD)
@@ -318,11 +318,11 @@ static Result<T> GetParams(const IOCtlRequest& request)
   return params;
 }
 
-IPCCommandResult FSDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> FSDevice::IOCtl(const IOCtlRequest& request)
 {
   const auto it = m_fd_map.find(request.fd);
   if (it == m_fd_map.end())
-    return GetDefaultReply(ConvertResult(ResultCode::Invalid));
+    return IPCReply(ConvertResult(ResultCode::Invalid));
 
   switch (request.request)
   {
@@ -353,11 +353,11 @@ IPCCommandResult FSDevice::IOCtl(const IOCtlRequest& request)
   }
 }
 
-IPCCommandResult FSDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> FSDevice::IOCtlV(const IOCtlVRequest& request)
 {
   const auto it = m_fd_map.find(request.fd);
   if (it == m_fd_map.end())
-    return GetDefaultReply(ConvertResult(ResultCode::Invalid));
+    return IPCReply(ConvertResult(ResultCode::Invalid));
 
   switch (request.request)
   {
@@ -370,7 +370,7 @@ IPCCommandResult FSDevice::IOCtlV(const IOCtlVRequest& request)
   }
 }
 
-IPCCommandResult FSDevice::Format(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::Format(const Handle& handle, const IOCtlRequest& request)
 {
   if (handle.uid != 0)
     return GetFSReply(ConvertResult(ResultCode::AccessDenied));
@@ -379,7 +379,7 @@ IPCCommandResult FSDevice::Format(const Handle& handle, const IOCtlRequest& requ
   return GetReplyForSuperblockOperation(result);
 }
 
-IPCCommandResult FSDevice::GetStats(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::GetStats(const Handle& handle, const IOCtlRequest& request)
 {
   if (request.buffer_out_size < sizeof(ISFSNandStats))
     return GetFSReply(ConvertResult(ResultCode::Invalid));
@@ -387,7 +387,7 @@ IPCCommandResult FSDevice::GetStats(const Handle& handle, const IOCtlRequest& re
   const Result<NandStats> stats = m_ios.GetFS()->GetNandStats();
   LogResult(stats, "GetNandStats");
   if (!stats)
-    return GetDefaultReply(ConvertResult(stats.Error()));
+    return IPCReply(ConvertResult(stats.Error()));
 
   ISFSNandStats out;
   out.cluster_size = stats->cluster_size;
@@ -398,10 +398,10 @@ IPCCommandResult FSDevice::GetStats(const Handle& handle, const IOCtlRequest& re
   out.free_inodes = stats->free_inodes;
   out.used_inodes = stats->used_inodes;
   Memory::CopyToEmu(request.buffer_out, &out, sizeof(out));
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult FSDevice::CreateDirectory(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::CreateDirectory(const Handle& handle, const IOCtlRequest& request)
 {
   const auto params = GetParams<ISFSParams>(request);
   if (!params)
@@ -413,7 +413,7 @@ IPCCommandResult FSDevice::CreateDirectory(const Handle& handle, const IOCtlRequ
   return GetReplyForSuperblockOperation(result);
 }
 
-IPCCommandResult FSDevice::ReadDirectory(const Handle& handle, const IOCtlVRequest& request)
+IPCReply FSDevice::ReadDirectory(const Handle& handle, const IOCtlVRequest& request)
 {
   if (request.in_vectors.empty() || request.in_vectors.size() != request.io_vectors.size() ||
       request.in_vectors.size() > 2 || request.in_vectors[0].size != 64)
@@ -467,7 +467,7 @@ IPCCommandResult FSDevice::ReadDirectory(const Handle& handle, const IOCtlVReque
   return GetFSReply(IPC_SUCCESS);
 }
 
-IPCCommandResult FSDevice::SetAttribute(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::SetAttribute(const Handle& handle, const IOCtlRequest& request)
 {
   const auto params = GetParams<ISFSParams>(request);
   if (!params)
@@ -479,7 +479,7 @@ IPCCommandResult FSDevice::SetAttribute(const Handle& handle, const IOCtlRequest
   return GetReplyForSuperblockOperation(result);
 }
 
-IPCCommandResult FSDevice::GetAttribute(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::GetAttribute(const Handle& handle, const IOCtlRequest& request)
 {
   if (request.buffer_in_size < 64 || request.buffer_out_size < sizeof(ISFSParams))
     return GetFSReply(ConvertResult(ResultCode::Invalid));
@@ -503,7 +503,7 @@ IPCCommandResult FSDevice::GetAttribute(const Handle& handle, const IOCtlRequest
   return GetFSReply(IPC_SUCCESS, ticks);
 }
 
-IPCCommandResult FSDevice::DeleteFile(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::DeleteFile(const Handle& handle, const IOCtlRequest& request)
 {
   if (request.buffer_in_size < 64)
     return GetFSReply(ConvertResult(ResultCode::Invalid));
@@ -514,7 +514,7 @@ IPCCommandResult FSDevice::DeleteFile(const Handle& handle, const IOCtlRequest&
   return GetReplyForSuperblockOperation(result);
 }
 
-IPCCommandResult FSDevice::RenameFile(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::RenameFile(const Handle& handle, const IOCtlRequest& request)
 {
   if (request.buffer_in_size < 64 * 2)
     return GetFSReply(ConvertResult(ResultCode::Invalid));
@@ -526,7 +526,7 @@ IPCCommandResult FSDevice::RenameFile(const Handle& handle, const IOCtlRequest&
   return GetReplyForSuperblockOperation(result);
 }
 
-IPCCommandResult FSDevice::CreateFile(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::CreateFile(const Handle& handle, const IOCtlRequest& request)
 {
   const auto params = GetParams<ISFSParams>(request);
   if (!params)
@@ -538,7 +538,7 @@ IPCCommandResult FSDevice::CreateFile(const Handle& handle, const IOCtlRequest&
   return GetReplyForSuperblockOperation(result);
 }
 
-IPCCommandResult FSDevice::SetFileVersionControl(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::SetFileVersionControl(const Handle& handle, const IOCtlRequest& request)
 {
   const auto params = GetParams<ISFSParams>(request);
   if (!params)
@@ -550,7 +550,7 @@ IPCCommandResult FSDevice::SetFileVersionControl(const Handle& handle, const IOC
   return GetFSReply(IPC_SUCCESS);
 }
 
-IPCCommandResult FSDevice::GetFileStats(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::GetFileStats(const Handle& handle, const IOCtlRequest& request)
 {
   if (request.buffer_out_size < 8 || handle.fs_fd == INVALID_FD)
     return GetFSReply(ConvertResult(ResultCode::Invalid));
@@ -558,16 +558,16 @@ IPCCommandResult FSDevice::GetFileStats(const Handle& handle, const IOCtlRequest
   const Result<FileStatus> status = m_ios.GetFS()->GetFileStatus(handle.fs_fd);
   LogResult(status, "GetFileStatus({})", handle.name.data());
   if (!status)
-    return GetDefaultReply(ConvertResult(status.Error()));
+    return IPCReply(ConvertResult(status.Error()));
 
   ISFSFileStats out;
   out.size = status->size;
   out.seek_position = status->offset;
   Memory::CopyToEmu(request.buffer_out, &out, sizeof(out));
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult FSDevice::GetUsage(const Handle& handle, const IOCtlVRequest& request)
+IPCReply FSDevice::GetUsage(const Handle& handle, const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 2) || request.in_vectors[0].size != 64 ||
       request.io_vectors[0].size != 4 || request.io_vectors[1].size != 4)
@@ -586,7 +586,7 @@ IPCCommandResult FSDevice::GetUsage(const Handle& handle, const IOCtlVRequest& r
   return GetFSReply(IPC_SUCCESS);
 }
 
-IPCCommandResult FSDevice::Shutdown(const Handle& handle, const IOCtlRequest& request)
+IPCReply FSDevice::Shutdown(const Handle& handle, const IOCtlRequest& request)
 {
   INFO_LOG_FMT(IOS_FS, "Shutdown");
   return GetFSReply(IPC_SUCCESS);
diff --git a/Source/Core/Core/IOS/FS/FileSystemProxy.h b/Source/Core/Core/IOS/FS/FileSystemProxy.h
index ff8d315e04..e2967eb5dc 100644
--- a/Source/Core/Core/IOS/FS/FileSystemProxy.h
+++ b/Source/Core/Core/IOS/FS/FileSystemProxy.h
@@ -26,13 +26,13 @@ public:
 
   void DoState(PointerWrap& p) override;
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult Close(u32 fd) override;
-  IPCCommandResult Read(const ReadWriteRequest& request) override;
-  IPCCommandResult Write(const ReadWriteRequest& request) override;
-  IPCCommandResult Seek(const SeekRequest& request) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Close(u32 fd) override;
+  std::optional<IPCReply> Read(const ReadWriteRequest& request) override;
+  std::optional<IPCReply> Write(const ReadWriteRequest& request) override;
+  std::optional<IPCReply> Seek(const SeekRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
 private:
   struct Handle
@@ -62,19 +62,19 @@ private:
     ISFS_IOCTL_SHUTDOWN = 13,
   };
 
-  IPCCommandResult Format(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult GetStats(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult CreateDirectory(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult ReadDirectory(const Handle& handle, const IOCtlVRequest& request);
-  IPCCommandResult SetAttribute(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult GetAttribute(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult DeleteFile(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult RenameFile(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult CreateFile(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult SetFileVersionControl(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult GetFileStats(const Handle& handle, const IOCtlRequest& request);
-  IPCCommandResult GetUsage(const Handle& handle, const IOCtlVRequest& request);
-  IPCCommandResult Shutdown(const Handle& handle, const IOCtlRequest& request);
+  IPCReply Format(const Handle& handle, const IOCtlRequest& request);
+  IPCReply GetStats(const Handle& handle, const IOCtlRequest& request);
+  IPCReply CreateDirectory(const Handle& handle, const IOCtlRequest& request);
+  IPCReply ReadDirectory(const Handle& handle, const IOCtlVRequest& request);
+  IPCReply SetAttribute(const Handle& handle, const IOCtlRequest& request);
+  IPCReply GetAttribute(const Handle& handle, const IOCtlRequest& request);
+  IPCReply DeleteFile(const Handle& handle, const IOCtlRequest& request);
+  IPCReply RenameFile(const Handle& handle, const IOCtlRequest& request);
+  IPCReply CreateFile(const Handle& handle, const IOCtlRequest& request);
+  IPCReply SetFileVersionControl(const Handle& handle, const IOCtlRequest& request);
+  IPCReply GetFileStats(const Handle& handle, const IOCtlRequest& request);
+  IPCReply GetUsage(const Handle& handle, const IOCtlVRequest& request);
+  IPCReply Shutdown(const Handle& handle, const IOCtlRequest& request);
 
   u64 EstimateTicksForReadWrite(const Handle& handle, const ReadWriteRequest& request);
   u64 SimulatePopulateFileCache(u32 fd, u32 offset, u32 file_size);
diff --git a/Source/Core/Core/IOS/IOS.cpp b/Source/Core/Core/IOS/IOS.cpp
index 61986a0593..19992f8f9e 100644
--- a/Source/Core/Core/IOS/IOS.cpp
+++ b/Source/Core/Core/IOS/IOS.cpp
@@ -518,14 +518,14 @@ std::shared_ptr<Device> EmulationKernel::GetDeviceByName(std::string_view device
 }
 
 // Returns the FD for the newly opened device (on success) or an error code.
-IPCCommandResult Kernel::OpenDevice(OpenRequest& request)
+std::optional<IPCReply> Kernel::OpenDevice(OpenRequest& request)
 {
   const s32 new_fd = GetFreeDeviceID();
   INFO_LOG_FMT(IOS, "Opening {} (mode {}, fd {})", request.path, request.flags, new_fd);
   if (new_fd < 0 || new_fd >= IPC_MAX_FDS)
   {
     ERROR_LOG_FMT(IOS, "Couldn't get a free fd, too many open files");
-    return IPCCommandResult{IPC_EMAX, true, 5000 * SystemTimers::TIMER_RATIO};
+    return IPCReply{IPC_EMAX, 5000_tbticks};
   }
   request.fd = new_fd;
 
@@ -547,22 +547,22 @@ IPCCommandResult Kernel::OpenDevice(OpenRequest& request)
   if (!device)
   {
     ERROR_LOG_FMT(IOS, "Unknown device: {}", request.path);
-    return {IPC_ENOENT, true, 3700 * SystemTimers::TIMER_RATIO};
+    return IPCReply{IPC_ENOENT, 3700_tbticks};
   }
 
-  IPCCommandResult result = device->Open(request);
-  if (result.return_value >= IPC_SUCCESS)
+  std::optional<IPCReply> result = device->Open(request);
+  if (result && result->return_value >= IPC_SUCCESS)
   {
     m_fdmap[new_fd] = device;
-    result.return_value = new_fd;
+    result->return_value = new_fd;
   }
   return result;
 }
 
-IPCCommandResult Kernel::HandleIPCCommand(const Request& request)
+std::optional<IPCReply> Kernel::HandleIPCCommand(const Request& request)
 {
   if (request.command < IPC_CMD_OPEN || request.command > IPC_CMD_IOCTLV)
-    return IPCCommandResult{IPC_EINVAL, true, 978 * SystemTimers::TIMER_RATIO};
+    return IPCReply{IPC_EINVAL, 978_tbticks};
 
   if (request.command == IPC_CMD_OPEN)
   {
@@ -572,9 +572,9 @@ IPCCommandResult Kernel::HandleIPCCommand(const Request& request)
 
   const auto device = (request.fd < IPC_MAX_FDS) ? m_fdmap[request.fd] : nullptr;
   if (!device)
-    return IPCCommandResult{IPC_EINVAL, true, 550 * SystemTimers::TIMER_RATIO};
+    return IPCReply{IPC_EINVAL, 550_tbticks};
 
-  IPCCommandResult ret;
+  std::optional<IPCReply> ret;
   const u64 wall_time_before = Common::Timer::GetTimeUs();
 
   switch (request.command)
@@ -600,7 +600,7 @@ IPCCommandResult Kernel::HandleIPCCommand(const Request& request)
     break;
   default:
     ASSERT_MSG(IOS, false, "Unexpected command: %x", request.command);
-    ret = IPCCommandResult{IPC_EINVAL, true, 978 * SystemTimers::TIMER_RATIO};
+    ret = IPCReply{IPC_EINVAL, 978_tbticks};
     break;
   }
 
@@ -618,18 +618,18 @@ IPCCommandResult Kernel::HandleIPCCommand(const Request& request)
 void Kernel::ExecuteIPCCommand(const u32 address)
 {
   Request request{address};
-  IPCCommandResult result = HandleIPCCommand(request);
+  std::optional<IPCReply> result = HandleIPCCommand(request);
 
-  if (!result.send_reply)
+  if (!result)
     return;
 
   // Ensure replies happen in order
   const s64 ticks_until_last_reply = m_last_reply_time - CoreTiming::GetTicks();
   if (ticks_until_last_reply > 0)
-    result.reply_delay_ticks += ticks_until_last_reply;
-  m_last_reply_time = CoreTiming::GetTicks() + result.reply_delay_ticks;
+    result->reply_delay_ticks += ticks_until_last_reply;
+  m_last_reply_time = CoreTiming::GetTicks() + result->reply_delay_ticks;
 
-  EnqueueIPCReply(request, result.return_value, static_cast<int>(result.reply_delay_ticks));
+  EnqueueIPCReply(request, result->return_value, result->reply_delay_ticks);
 }
 
 // Happens AS SOON AS IPC gets a new pointer!
@@ -638,12 +638,11 @@ void Kernel::EnqueueIPCRequest(u32 address)
   // Based on hardware tests, IOS takes between 5µs and 10µs to acknowledge an IPC request.
   // Console 1: 456 TB ticks before ACK
   // Console 2: 658 TB ticks before ACK
-  CoreTiming::ScheduleEvent(500 * SystemTimers::TIMER_RATIO, s_event_enqueue,
-                            address | ENQUEUE_REQUEST_FLAG);
+  CoreTiming::ScheduleEvent(500_tbticks, s_event_enqueue, address | ENQUEUE_REQUEST_FLAG);
 }
 
 // Called to send a reply to an IOS syscall
-void Kernel::EnqueueIPCReply(const Request& request, const s32 return_value, int cycles_in_future,
+void Kernel::EnqueueIPCReply(const Request& request, const s32 return_value, s64 cycles_in_future,
                              CoreTiming::FromThread from)
 {
   Memory::Write_U32(static_cast<u32>(return_value), request.address + 4);
@@ -852,4 +851,20 @@ EmulationKernel* GetIOS()
 {
   return s_ios.get();
 }
+
+// Based on a hardware test, a device takes at least ~2700 ticks to reply to an IPC request.
+// Depending on how much work a command performs, this can take much longer (10000+)
+// especially if the NAND filesystem is accessed.
+//
+// Because we currently don't emulate timing very accurately, we should not return
+// the minimum possible reply time (~960 ticks from the kernel or ~2700 from devices)
+// but an average value, otherwise we are going to be much too fast in most cases.
+IPCReply::IPCReply(s32 return_value_) : IPCReply(return_value_, 4000_tbticks)
+{
+}
+
+IPCReply::IPCReply(s32 return_value_, u64 reply_delay_ticks_)
+    : return_value(return_value_), reply_delay_ticks(reply_delay_ticks_)
+{
+}
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/IOS.h b/Source/Core/Core/IOS/IOS.h
index 6d2ec6fa14..ba823894b9 100644
--- a/Source/Core/Core/IOS/IOS.h
+++ b/Source/Core/Core/IOS/IOS.h
@@ -9,6 +9,7 @@
 #include <map>
 #include <memory>
 #include <mutex>
+#include <optional>
 #include <string>
 #include <string_view>
 #include <vector>
@@ -33,10 +34,14 @@ class ESDevice;
 struct Request;
 struct OpenRequest;
 
-struct IPCCommandResult
+struct IPCReply
 {
+  /// Constructs a reply with an average reply time.
+  /// Please avoid using this function if more accurate timings are known.
+  explicit IPCReply(s32 return_value_);
+  explicit IPCReply(s32 return_value_, u64 reply_delay_ticks_);
+
   s32 return_value;
-  bool send_reply;
   u64 reply_delay_ticks;
 };
 
@@ -84,7 +89,7 @@ public:
   void SDIO_EventNotify();
 
   void EnqueueIPCRequest(u32 address);
-  void EnqueueIPCReply(const Request& request, s32 return_value, int cycles_in_future = 0,
+  void EnqueueIPCReply(const Request& request, s32 return_value, s64 cycles_in_future = 0,
                        CoreTiming::FromThread from = CoreTiming::FromThread::CPU);
 
   void SetUidForPPC(u32 uid);
@@ -102,7 +107,7 @@ protected:
   explicit Kernel(u64 title_id);
 
   void ExecuteIPCCommand(u32 address);
-  IPCCommandResult HandleIPCCommand(const Request& request);
+  std::optional<IPCReply> HandleIPCCommand(const Request& request);
   void EnqueueIPCAcknowledgement(u32 address, int cycles_in_future = 0);
 
   void AddDevice(std::unique_ptr<Device> device);
@@ -110,7 +115,7 @@ protected:
   void AddStaticDevices();
   std::shared_ptr<Device> GetDeviceByName(std::string_view device_name);
   s32 GetFreeDeviceID();
-  IPCCommandResult OpenDevice(OpenRequest& request);
+  std::optional<IPCReply> OpenDevice(OpenRequest& request);
 
   bool m_is_responsible_for_nand_root = false;
   u64 m_title_id = 0;
diff --git a/Source/Core/Core/IOS/Network/IP/Top.cpp b/Source/Core/Core/IOS/Network/IP/Top.cpp
index ba2fda786d..88a91d7a02 100644
--- a/Source/Core/Core/IOS/Network/IP/Top.cpp
+++ b/Source/Core/Core/IOS/Network/IP/Top.cpp
@@ -285,11 +285,11 @@ static DefaultInterface GetSystemDefaultInterfaceOrFallback()
   return GetSystemDefaultInterface().value_or(FALLBACK_VALUES);
 }
 
-IPCCommandResult NetIPTopDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> NetIPTopDevice::IOCtl(const IOCtlRequest& request)
 {
   if (Core::WantsDeterminism())
   {
-    return GetDefaultReply(IPC_EACCES);
+    return IPCReply(IPC_EACCES);
   }
 
   switch (request.request)
@@ -339,10 +339,10 @@ IPCCommandResult NetIPTopDevice::IOCtl(const IOCtlRequest& request)
     break;
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult NetIPTopDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> NetIPTopDevice::IOCtlV(const IOCtlVRequest& request)
 {
   switch (request.request)
   {
@@ -361,7 +361,7 @@ IPCCommandResult NetIPTopDevice::IOCtlV(const IOCtlVRequest& request)
     break;
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 void NetIPTopDevice::Update()
@@ -369,13 +369,13 @@ void NetIPTopDevice::Update()
   WiiSockMan::GetInstance().Update();
 }
 
-IPCCommandResult NetIPTopDevice::HandleInitInterfaceRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleInitInterfaceRequest(const IOCtlRequest& request)
 {
   request.Log(GetDeviceName(), Common::Log::IOS_WC24);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult NetIPTopDevice::HandleSocketRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleSocketRequest(const IOCtlRequest& request)
 {
   const u32 af = Memory::Read_U32(request.buffer_in);
   const u32 type = Memory::Read_U32(request.buffer_in + 4);
@@ -389,20 +389,20 @@ IPCCommandResult NetIPTopDevice::HandleSocketRequest(const IOCtlRequest& request
                return_value, af, type, prot, request.buffer_in, request.buffer_in_size,
                request.buffer_out, request.buffer_out_size);
 
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
-IPCCommandResult NetIPTopDevice::HandleICMPSocketRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleICMPSocketRequest(const IOCtlRequest& request)
 {
   const u32 pf = Memory::Read_U32(request.buffer_in);
 
   WiiSockMan& sm = WiiSockMan::GetInstance();
   const s32 return_value = sm.NewSocket(pf, SOCK_RAW, IPPROTO_ICMP);
   INFO_LOG_FMT(IOS_NET, "IOCTL_SO_ICMPSOCKET({:x}) {}", pf, return_value);
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
-IPCCommandResult NetIPTopDevice::HandleCloseRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleCloseRequest(const IOCtlRequest& request)
 {
   const u32 fd = Memory::Read_U32(request.buffer_in);
   WiiSockMan& sm = WiiSockMan::GetInstance();
@@ -412,24 +412,24 @@ IPCCommandResult NetIPTopDevice::HandleCloseRequest(const IOCtlRequest& request)
 
   INFO_LOG_FMT(IOS_NET, "{}({:x}) {:x}", close_fn, fd, return_value);
 
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
-IPCCommandResult NetIPTopDevice::HandleDoSockRequest(const IOCtlRequest& request)
+std::optional<IPCReply> NetIPTopDevice::HandleDoSockRequest(const IOCtlRequest& request)
 {
   const u32 fd = Memory::Read_U32(request.buffer_in);
   WiiSockMan& sm = WiiSockMan::GetInstance();
   sm.DoSock(fd, request, static_cast<NET_IOCTL>(request.request));
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult NetIPTopDevice::HandleShutdownRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleShutdownRequest(const IOCtlRequest& request)
 {
   if (request.buffer_in == 0 || request.buffer_in_size < 8)
   {
     ERROR_LOG_FMT(IOS_NET, "IOCTL_SO_SHUTDOWN = EINVAL, BufferIn: ({:08x}, {})", request.buffer_in,
                   request.buffer_in_size);
-    return GetDefaultReply(-SO_EINVAL);
+    return IPCReply(-SO_EINVAL);
   }
 
   const u32 fd = Memory::Read_U32(request.buffer_in);
@@ -438,20 +438,20 @@ IPCCommandResult NetIPTopDevice::HandleShutdownRequest(const IOCtlRequest& reque
   const s32 return_value = sm.ShutdownSocket(fd, how);
 
   INFO_LOG_FMT(IOS_NET, "IOCTL_SO_SHUTDOWN(fd={}, how={}) = {}", fd, how, return_value);
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
-IPCCommandResult NetIPTopDevice::HandleListenRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleListenRequest(const IOCtlRequest& request)
 {
   u32 fd = Memory::Read_U32(request.buffer_in);
   u32 BACKLOG = Memory::Read_U32(request.buffer_in + 0x04);
   u32 ret = listen(WiiSockMan::GetInstance().GetHostSocket(fd), BACKLOG);
 
   request.Log(GetDeviceName(), Common::Log::IOS_WC24);
-  return GetDefaultReply(WiiSockMan::GetNetErrorCode(ret, "SO_LISTEN", false));
+  return IPCReply(WiiSockMan::GetNetErrorCode(ret, "SO_LISTEN", false));
 }
 
-IPCCommandResult NetIPTopDevice::HandleGetSockOptRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleGetSockOptRequest(const IOCtlRequest& request)
 {
   u32 fd = Memory::Read_U32(request.buffer_out);
   u32 level = Memory::Read_U32(request.buffer_out + 4);
@@ -481,10 +481,10 @@ IPCCommandResult NetIPTopDevice::HandleGetSockOptRequest(const IOCtlRequest& req
     Memory::Write_U32(last_error, request.buffer_out + 0x10);
   }
 
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
-IPCCommandResult NetIPTopDevice::HandleSetSockOptRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleSetSockOptRequest(const IOCtlRequest& request)
 {
   const u32 fd = Memory::Read_U32(request.buffer_in);
   const u32 level = Memory::Read_U32(request.buffer_in + 4);
@@ -508,7 +508,7 @@ IPCCommandResult NetIPTopDevice::HandleSetSockOptRequest(const IOCtlRequest& req
   // TODO: bug booto about this, 0x2005 most likely timeout related, default value on Wii is ,
   // 0x2001 is most likely tcpnodelay
   if (level == 6 && (optname == 0x2005 || optname == 0x2001))
-    return GetDefaultReply(0);
+    return IPCReply(0);
 
   // Do the level/optname translation
   const int nat_level = MapWiiSockOptLevelToNative(level);
@@ -516,10 +516,10 @@ IPCCommandResult NetIPTopDevice::HandleSetSockOptRequest(const IOCtlRequest& req
 
   const int ret = setsockopt(WiiSockMan::GetInstance().GetHostSocket(fd), nat_level, nat_optname,
                              reinterpret_cast<char*>(optval), optlen);
-  return GetDefaultReply(WiiSockMan::GetNetErrorCode(ret, "SO_SETSOCKOPT", false));
+  return IPCReply(WiiSockMan::GetNetErrorCode(ret, "SO_SETSOCKOPT", false));
 }
 
-IPCCommandResult NetIPTopDevice::HandleGetSockNameRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleGetSockNameRequest(const IOCtlRequest& request)
 {
   u32 fd = Memory::Read_U32(request.buffer_in);
 
@@ -542,10 +542,10 @@ IPCCommandResult NetIPTopDevice::HandleGetSockNameRequest(const IOCtlRequest& re
                       std::min<size_t>(sizeof(sa.sa_data), request.buffer_out_size - 2));
   }
 
-  return GetDefaultReply(ret);
+  return IPCReply(ret);
 }
 
-IPCCommandResult NetIPTopDevice::HandleGetPeerNameRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleGetPeerNameRequest(const IOCtlRequest& request)
 {
   u32 fd = Memory::Read_U32(request.buffer_in);
 
@@ -567,19 +567,19 @@ IPCCommandResult NetIPTopDevice::HandleGetPeerNameRequest(const IOCtlRequest& re
   }
 
   INFO_LOG_FMT(IOS_NET, "IOCTL_SO_GETPEERNAME({:x})", fd);
-  return GetDefaultReply(ret);
+  return IPCReply(ret);
 }
 
-IPCCommandResult NetIPTopDevice::HandleGetHostIDRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleGetHostIDRequest(const IOCtlRequest& request)
 {
   const DefaultInterface interface = GetSystemDefaultInterfaceOrFallback();
   const u32 host_ip = Common::swap32(interface.inet);
   INFO_LOG_FMT(IOS_NET, "IOCTL_SO_GETHOSTID = {}.{}.{}.{}", host_ip >> 24, (host_ip >> 16) & 0xFF,
                (host_ip >> 8) & 0xFF, host_ip & 0xFF);
-  return GetDefaultReply(host_ip);
+  return IPCReply(host_ip);
 }
 
-IPCCommandResult NetIPTopDevice::HandleInetAToNRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleInetAToNRequest(const IOCtlRequest& request)
 {
   const std::string hostname = Memory::GetString(request.buffer_in);
   struct hostent* remoteHost = gethostbyname(hostname.c_str());
@@ -593,7 +593,7 @@ IPCCommandResult NetIPTopDevice::HandleInetAToNRequest(const IOCtlRequest& reque
                  hostname, request.buffer_in, request.buffer_in_size, request.buffer_out,
                  request.buffer_out_size);
 
-    return GetDefaultReply(0);
+    return IPCReply(0);
   }
 
   const auto ip = Common::swap32(reinterpret_cast<u8*>(remoteHost->h_addr_list[0]));
@@ -605,17 +605,17 @@ IPCCommandResult NetIPTopDevice::HandleInetAToNRequest(const IOCtlRequest& reque
                hostname, request.buffer_in, request.buffer_in_size, request.buffer_out,
                request.buffer_out_size, ip);
 
-  return GetDefaultReply(1);
+  return IPCReply(1);
 }
 
-IPCCommandResult NetIPTopDevice::HandleInetPToNRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleInetPToNRequest(const IOCtlRequest& request)
 {
   const std::string address = Memory::GetString(request.buffer_in);
   INFO_LOG_FMT(IOS_NET, "IOCTL_SO_INETPTON (Translating: {})", address);
-  return GetDefaultReply(inet_pton(address.c_str(), Memory::GetPointer(request.buffer_out + 4)));
+  return IPCReply(inet_pton(address.c_str(), Memory::GetPointer(request.buffer_out + 4)));
 }
 
-IPCCommandResult NetIPTopDevice::HandleInetNToPRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleInetNToPRequest(const IOCtlRequest& request)
 {
   // u32 af = Memory::Read_U32(BufferIn);
   // u32 validAddress = Memory::Read_U32(request.buffer_in + 4);
@@ -628,15 +628,15 @@ IPCCommandResult NetIPTopDevice::HandleInetNToPRequest(const IOCtlRequest& reque
 
   INFO_LOG_FMT(IOS_NET, "IOCTL_SO_INETNTOP {}", ip_s);
   Memory::CopyToEmu(request.buffer_out, reinterpret_cast<u8*>(ip_s), std::strlen(ip_s));
-  return GetDefaultReply(0);
+  return IPCReply(0);
 }
 
-IPCCommandResult NetIPTopDevice::HandlePollRequest(const IOCtlRequest& request)
+std::optional<IPCReply> NetIPTopDevice::HandlePollRequest(const IOCtlRequest& request)
 {
   WiiSockMan& sm = WiiSockMan::GetInstance();
 
   if (!request.buffer_in || !request.buffer_out)
-    return GetDefaultReply(-SO_EINVAL);
+    return IPCReply(-SO_EINVAL);
 
   // Negative timeout indicates wait forever
   const s64 timeout = static_cast<s64>(Memory::Read_U64(request.buffer_in));
@@ -645,7 +645,7 @@ IPCCommandResult NetIPTopDevice::HandlePollRequest(const IOCtlRequest& request)
   if (nfds == 0 || nfds > WII_SOCKET_FD_MAX)
   {
     ERROR_LOG_FMT(IOS_NET, "IOCTL_SO_POLL failed: Invalid array size {}, ret={}", nfds, -SO_EINVAL);
-    return GetDefaultReply(-SO_EINVAL);
+    return IPCReply(-SO_EINVAL);
   }
 
   std::vector<pollfd_t> ufds(nfds);
@@ -671,15 +671,15 @@ IPCCommandResult NetIPTopDevice::HandlePollRequest(const IOCtlRequest& request)
 
   // Prevents blocking emulation on a blocking poll
   sm.AddPollCommand({request.address, request.buffer_out, std::move(ufds), timeout});
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult NetIPTopDevice::HandleGetHostByNameRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleGetHostByNameRequest(const IOCtlRequest& request)
 {
   if (request.buffer_out_size != 0x460)
   {
     ERROR_LOG_FMT(IOS_NET, "Bad buffer size for IOCTL_SO_GETHOSTBYNAME");
-    return GetDefaultReply(-1);
+    return IPCReply(-1);
   }
 
   const std::string hostname = Memory::GetString(request.buffer_in);
@@ -692,7 +692,7 @@ IPCCommandResult NetIPTopDevice::HandleGetHostByNameRequest(const IOCtlRequest&
                request.buffer_out_size);
 
   if (remoteHost == nullptr)
-    return GetDefaultReply(-1);
+    return IPCReply(-1);
 
   for (int i = 0; remoteHost->h_aliases[i]; ++i)
   {
@@ -715,7 +715,7 @@ IPCCommandResult NetIPTopDevice::HandleGetHostByNameRequest(const IOCtlRequest&
   if (name_length > (GETHOSTBYNAME_IP_LIST_OFFSET - GETHOSTBYNAME_STRUCT_SIZE))
   {
     ERROR_LOG_FMT(IOS_NET, "Hostname too long in IOCTL_SO_GETHOSTBYNAME");
-    return GetDefaultReply(-1);
+    return IPCReply(-1);
   }
   Memory::CopyToEmu(request.buffer_out + GETHOSTBYNAME_STRUCT_SIZE, remoteHost->h_name,
                     name_length);
@@ -757,16 +757,16 @@ IPCCommandResult NetIPTopDevice::HandleGetHostByNameRequest(const IOCtlRequest&
   Memory::Write_U16(AF_INET, request.buffer_out + 8);
   Memory::Write_U16(sizeof(u32), request.buffer_out + 10);
 
-  return GetDefaultReply(0);
+  return IPCReply(0);
 }
 
-IPCCommandResult NetIPTopDevice::HandleICMPCancelRequest(const IOCtlRequest& request)
+IPCReply NetIPTopDevice::HandleICMPCancelRequest(const IOCtlRequest& request)
 {
   ERROR_LOG_FMT(IOS_NET, "IOCTL_SO_ICMPCANCEL");
-  return GetDefaultReply(0);
+  return IPCReply(0);
 }
 
-IPCCommandResult NetIPTopDevice::HandleGetInterfaceOptRequest(const IOCtlVRequest& request)
+IPCReply NetIPTopDevice::HandleGetInterfaceOptRequest(const IOCtlVRequest& request)
 {
   const u32 param = Memory::Read_U32(request.in_vectors[0].address);
   const u32 param2 = Memory::Read_U32(request.in_vectors[0].address + 4);
@@ -777,7 +777,7 @@ IPCCommandResult NetIPTopDevice::HandleGetInterfaceOptRequest(const IOCtlVReques
   if (param != 0xfffe)
   {
     WARN_LOG_FMT(IOS_NET, "GetInterfaceOpt: received invalid request with param0={:08x}", param);
-    return GetDefaultReply(SO_ERROR_INVALID_REQUEST);
+    return IPCReply(SO_ERROR_INVALID_REQUEST);
   }
 
   if (request.io_vectors[0].size >= 8)
@@ -939,26 +939,26 @@ IPCCommandResult NetIPTopDevice::HandleGetInterfaceOptRequest(const IOCtlVReques
     break;
   }
 
-  return GetDefaultReply(0);
+  return IPCReply(0);
 }
 
-IPCCommandResult NetIPTopDevice::HandleSendToRequest(const IOCtlVRequest& request)
+std::optional<IPCReply> NetIPTopDevice::HandleSendToRequest(const IOCtlVRequest& request)
 {
   u32 fd = Memory::Read_U32(request.in_vectors[1].address);
   WiiSockMan& sm = WiiSockMan::GetInstance();
   sm.DoSock(fd, request, IOCTLV_SO_SENDTO);
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult NetIPTopDevice::HandleRecvFromRequest(const IOCtlVRequest& request)
+std::optional<IPCReply> NetIPTopDevice::HandleRecvFromRequest(const IOCtlVRequest& request)
 {
   u32 fd = Memory::Read_U32(request.in_vectors[0].address);
   WiiSockMan& sm = WiiSockMan::GetInstance();
   sm.DoSock(fd, request, IOCTLV_SO_RECVFROM);
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult NetIPTopDevice::HandleGetAddressInfoRequest(const IOCtlVRequest& request)
+IPCReply NetIPTopDevice::HandleGetAddressInfoRequest(const IOCtlVRequest& request)
 {
   addrinfo hints;
   const bool hints_valid = request.in_vectors.size() > 2 && request.in_vectors[2].size;
@@ -1044,10 +1044,10 @@ IPCCommandResult NetIPTopDevice::HandleGetAddressInfoRequest(const IOCtlVRequest
   }
 
   request.Dump(GetDeviceName(), Common::Log::IOS_NET, Common::Log::LINFO);
-  return GetDefaultReply(ret);
+  return IPCReply(ret);
 }
 
-IPCCommandResult NetIPTopDevice::HandleICMPPingRequest(const IOCtlVRequest& request)
+IPCReply NetIPTopDevice::HandleICMPPingRequest(const IOCtlVRequest& request)
 {
   struct
   {
@@ -1111,6 +1111,6 @@ IPCCommandResult NetIPTopDevice::HandleICMPPingRequest(const IOCtlVRequest& requ
   }
 
   // TODO proper error codes
-  return GetDefaultReply(0);
+  return IPCReply(0);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/Network/IP/Top.h b/Source/Core/Core/IOS/Network/IP/Top.h
index f2ec7934ef..d87885d165 100644
--- a/Source/Core/Core/IOS/Network/IP/Top.h
+++ b/Source/Core/Core/IOS/Network/IP/Top.h
@@ -68,36 +68,36 @@ public:
   virtual ~NetIPTopDevice();
 
   void DoState(PointerWrap& p) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   void Update() override;
 
 private:
-  IPCCommandResult HandleInitInterfaceRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleSocketRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleICMPSocketRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleCloseRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleDoSockRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleShutdownRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleListenRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleGetSockOptRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleSetSockOptRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleGetSockNameRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleGetPeerNameRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleGetHostIDRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleInetAToNRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleInetPToNRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleInetNToPRequest(const IOCtlRequest& request);
-  IPCCommandResult HandlePollRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleGetHostByNameRequest(const IOCtlRequest& request);
-  IPCCommandResult HandleICMPCancelRequest(const IOCtlRequest& request);
+  IPCReply HandleInitInterfaceRequest(const IOCtlRequest& request);
+  IPCReply HandleSocketRequest(const IOCtlRequest& request);
+  IPCReply HandleICMPSocketRequest(const IOCtlRequest& request);
+  IPCReply HandleCloseRequest(const IOCtlRequest& request);
+  std::optional<IPCReply> HandleDoSockRequest(const IOCtlRequest& request);
+  IPCReply HandleShutdownRequest(const IOCtlRequest& request);
+  IPCReply HandleListenRequest(const IOCtlRequest& request);
+  IPCReply HandleGetSockOptRequest(const IOCtlRequest& request);
+  IPCReply HandleSetSockOptRequest(const IOCtlRequest& request);
+  IPCReply HandleGetSockNameRequest(const IOCtlRequest& request);
+  IPCReply HandleGetPeerNameRequest(const IOCtlRequest& request);
+  IPCReply HandleGetHostIDRequest(const IOCtlRequest& request);
+  IPCReply HandleInetAToNRequest(const IOCtlRequest& request);
+  IPCReply HandleInetPToNRequest(const IOCtlRequest& request);
+  IPCReply HandleInetNToPRequest(const IOCtlRequest& request);
+  std::optional<IPCReply> HandlePollRequest(const IOCtlRequest& request);
+  IPCReply HandleGetHostByNameRequest(const IOCtlRequest& request);
+  IPCReply HandleICMPCancelRequest(const IOCtlRequest& request);
 
-  IPCCommandResult HandleGetInterfaceOptRequest(const IOCtlVRequest& request);
-  IPCCommandResult HandleSendToRequest(const IOCtlVRequest& request);
-  IPCCommandResult HandleRecvFromRequest(const IOCtlVRequest& request);
-  IPCCommandResult HandleGetAddressInfoRequest(const IOCtlVRequest& request);
-  IPCCommandResult HandleICMPPingRequest(const IOCtlVRequest& request);
+  IPCReply HandleGetInterfaceOptRequest(const IOCtlVRequest& request);
+  std::optional<IPCReply> HandleSendToRequest(const IOCtlVRequest& request);
+  std::optional<IPCReply> HandleRecvFromRequest(const IOCtlVRequest& request);
+  IPCReply HandleGetAddressInfoRequest(const IOCtlVRequest& request);
+  IPCReply HandleICMPPingRequest(const IOCtlVRequest& request);
 
 #ifdef _WIN32
   WSADATA InitData;
diff --git a/Source/Core/Core/IOS/Network/KD/NetKDRequest.cpp b/Source/Core/Core/IOS/Network/KD/NetKDRequest.cpp
index 6a7f5dd1e9..6b61e8bfdb 100644
--- a/Source/Core/Core/IOS/Network/KD/NetKDRequest.cpp
+++ b/Source/Core/Core/IOS/Network/KD/NetKDRequest.cpp
@@ -32,7 +32,7 @@ NetKDRequestDevice::~NetKDRequestDevice()
   WiiSockMan::GetInstance().Clean();
 }
 
-IPCCommandResult NetKDRequestDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> NetKDRequestDevice::IOCtl(const IOCtlRequest& request)
 {
   s32 return_value = 0;
   switch (request.request)
@@ -169,7 +169,7 @@ IPCCommandResult NetKDRequestDevice::IOCtl(const IOCtlRequest& request)
     request.Log(GetDeviceName(), Common::Log::IOS_WC24);
   }
 
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
 u8 NetKDRequestDevice::GetAreaCode(const std::string& area) const
diff --git a/Source/Core/Core/IOS/Network/KD/NetKDRequest.h b/Source/Core/Core/IOS/Network/KD/NetKDRequest.h
index 8a0389d8dc..fd8b7e8efc 100644
--- a/Source/Core/Core/IOS/Network/KD/NetKDRequest.h
+++ b/Source/Core/Core/IOS/Network/KD/NetKDRequest.h
@@ -21,7 +21,7 @@ public:
   NetKDRequestDevice(Kernel& ios, const std::string& device_name);
   ~NetKDRequestDevice() override;
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
 
 private:
   enum
diff --git a/Source/Core/Core/IOS/Network/KD/NetKDTime.cpp b/Source/Core/Core/IOS/Network/KD/NetKDTime.cpp
index 756bc44639..8e73d602db 100644
--- a/Source/Core/Core/IOS/Network/KD/NetKDTime.cpp
+++ b/Source/Core/Core/IOS/Network/KD/NetKDTime.cpp
@@ -19,7 +19,7 @@ NetKDTimeDevice::NetKDTimeDevice(Kernel& ios, const std::string& device_name)
 
 NetKDTimeDevice::~NetKDTimeDevice() = default;
 
-IPCCommandResult NetKDTimeDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> NetKDTimeDevice::IOCtl(const IOCtlRequest& request)
 {
   s32 result = 0;
   u32 common_result = 0;
@@ -72,7 +72,7 @@ IPCCommandResult NetKDTimeDevice::IOCtl(const IOCtlRequest& request)
 
   // write return values
   Memory::Write_U32(common_result, request.buffer_out);
-  return GetDefaultReply(result);
+  return IPCReply(result);
 }
 
 u64 NetKDTimeDevice::GetAdjustedUTC() const
diff --git a/Source/Core/Core/IOS/Network/KD/NetKDTime.h b/Source/Core/Core/IOS/Network/KD/NetKDTime.h
index b09d2f23df..694107b6ac 100644
--- a/Source/Core/Core/IOS/Network/KD/NetKDTime.h
+++ b/Source/Core/Core/IOS/Network/KD/NetKDTime.h
@@ -17,7 +17,7 @@ public:
   NetKDTimeDevice(Kernel& ios, const std::string& device_name);
   ~NetKDTimeDevice() override;
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
 
 private:
   // TODO: depending on CEXIIPL is a hack which I don't feel like
diff --git a/Source/Core/Core/IOS/Network/NCD/Manage.cpp b/Source/Core/Core/IOS/Network/NCD/Manage.cpp
index 5e459adee0..b60846bc0d 100644
--- a/Source/Core/Core/IOS/Network/NCD/Manage.cpp
+++ b/Source/Core/Core/IOS/Network/NCD/Manage.cpp
@@ -27,7 +27,7 @@ void NetNCDManageDevice::DoState(PointerWrap& p)
   p.Do(m_ipc_fd);
 }
 
-IPCCommandResult NetNCDManageDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> NetNCDManageDevice::IOCtlV(const IOCtlVRequest& request)
 {
   s32 return_value = IPC_SUCCESS;
   u32 common_result = 0;
@@ -37,10 +37,10 @@ IPCCommandResult NetNCDManageDevice::IOCtlV(const IOCtlVRequest& request)
   {
   case IOCTLV_NCD_LOCKWIRELESSDRIVER:
     if (!request.HasNumberOfValidVectors(0, 1))
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
 
     if (request.io_vectors[0].size < 2 * sizeof(u32))
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
 
     if (m_ipc_fd != 0)
     {
@@ -60,13 +60,13 @@ IPCCommandResult NetNCDManageDevice::IOCtlV(const IOCtlVRequest& request)
   case IOCTLV_NCD_UNLOCKWIRELESSDRIVER:
   {
     if (!request.HasNumberOfValidVectors(1, 1))
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
 
     if (request.in_vectors[0].size < sizeof(u32))
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
 
     if (request.io_vectors[0].size < sizeof(u32))
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
 
     const u32 request_handle = Memory::Read_U32(request.in_vectors[0].address);
     if (m_ipc_fd == request_handle)
@@ -130,6 +130,6 @@ IPCCommandResult NetNCDManageDevice::IOCtlV(const IOCtlVRequest& request)
   {
     Memory::Write_U32(common_result, request.io_vectors.at(common_vector).address + 4);
   }
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/Network/NCD/Manage.h b/Source/Core/Core/IOS/Network/NCD/Manage.h
index 418fc493e5..75fe0a024c 100644
--- a/Source/Core/Core/IOS/Network/NCD/Manage.h
+++ b/Source/Core/Core/IOS/Network/NCD/Manage.h
@@ -18,7 +18,7 @@ class NetNCDManageDevice : public Device
 public:
   NetNCDManageDevice(Kernel& ios, const std::string& device_name);
 
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   void DoState(PointerWrap& p) override;
 
diff --git a/Source/Core/Core/IOS/Network/SSL.cpp b/Source/Core/Core/IOS/Network/SSL.cpp
index 0041cac59f..35ef3f7d79 100644
--- a/Source/Core/Core/IOS/Network/SSL.cpp
+++ b/Source/Core/Core/IOS/Network/SSL.cpp
@@ -113,10 +113,10 @@ int NetSSLDevice::GetSSLFreeID() const
   return 0;
 }
 
-IPCCommandResult NetSSLDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> NetSSLDevice::IOCtl(const IOCtlRequest& request)
 {
   request.Log(GetDeviceName(), Common::Log::IOS_SSL, Common::Log::LINFO);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 constexpr std::array<u8, 32> s_client_cert_hash = {
@@ -167,7 +167,7 @@ static std::vector<u8> ReadCertFile(const std::string& path, const std::array<u8
   return bytes;
 }
 
-IPCCommandResult NetSSLDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> NetSSLDevice::IOCtlV(const IOCtlVRequest& request)
 {
   u32 BufferIn = 0, BufferIn2 = 0, BufferIn3 = 0;
   u32 BufferInSize = 0, BufferInSize2 = 0, BufferInSize3 = 0;
@@ -210,7 +210,7 @@ IPCCommandResult NetSSLDevice::IOCtlV(const IOCtlVRequest& request)
   // I don't trust SSL to be deterministic, and this is never going to sync
   // as such (as opposed to forwarding IPC results or whatever), so -
   if (Core::WantsDeterminism())
-    return GetDefaultReply(IPC_EACCES);
+    return IPCReply(IPC_EACCES);
 
   switch (request.request)
   {
@@ -499,7 +499,7 @@ IPCCommandResult NetSSLDevice::IOCtlV(const IOCtlVRequest& request)
     {
       WiiSockMan& sm = WiiSockMan::GetInstance();
       sm.DoSock(_SSL[sslID].sockfd, request, IOCTLV_NET_SSL_DOHANDSHAKE);
-      return GetNoReply();
+      return std::nullopt;
     }
     else
     {
@@ -514,7 +514,7 @@ IPCCommandResult NetSSLDevice::IOCtlV(const IOCtlVRequest& request)
     {
       WiiSockMan& sm = WiiSockMan::GetInstance();
       sm.DoSock(_SSL[sslID].sockfd, request, IOCTLV_NET_SSL_WRITE);
-      return GetNoReply();
+      return std::nullopt;
     }
     else
     {
@@ -538,7 +538,7 @@ IPCCommandResult NetSSLDevice::IOCtlV(const IOCtlVRequest& request)
     {
       WiiSockMan& sm = WiiSockMan::GetInstance();
       sm.DoSock(_SSL[sslID].sockfd, request, IOCTLV_NET_SSL_READ);
-      return GetNoReply();
+      return std::nullopt;
     }
     else
     {
@@ -600,6 +600,6 @@ IPCCommandResult NetSSLDevice::IOCtlV(const IOCtlVRequest& request)
   }
 
   // SSL return codes are written to BufferIn
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/Network/SSL.h b/Source/Core/Core/IOS/Network/SSL.h
index 36f7fffc7c..fb92749c8e 100644
--- a/Source/Core/Core/IOS/Network/SSL.h
+++ b/Source/Core/Core/IOS/Network/SSL.h
@@ -87,8 +87,8 @@ public:
 
   virtual ~NetSSLDevice();
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   int GetSSLFreeID() const;
 
diff --git a/Source/Core/Core/IOS/Network/WD/Command.cpp b/Source/Core/Core/IOS/Network/WD/Command.cpp
index a18e154498..c64272a3d5 100644
--- a/Source/Core/Core/IOS/Network/WD/Command.cpp
+++ b/Source/Core/Core/IOS/Network/WD/Command.cpp
@@ -183,7 +183,7 @@ void NetWDCommandDevice::DoState(PointerWrap& p)
   p.Do(m_recv_notification_requests);
 }
 
-IPCCommandResult NetWDCommandDevice::Open(const OpenRequest& request)
+std::optional<IPCReply> NetWDCommandDevice::Open(const OpenRequest& request)
 {
   if (m_ipc_owner_fd < 0)
   {
@@ -197,7 +197,7 @@ IPCCommandResult NetWDCommandDevice::Open(const OpenRequest& request)
     {
       ERROR_LOG_FMT(IOS_NET, "Unsupported WD operating mode: {}", mode);
       DolphinAnalytics::Instance().ReportGameQuirk(GameQuirk::USES_UNCOMMON_WD_MODE);
-      return GetDefaultReply(s32(ResultCode::UnavailableCommand));
+      return IPCReply(s32(ResultCode::UnavailableCommand));
     }
 
     if (m_target_status == Status::Idle && mode <= WD::Mode::Unknown6)
@@ -212,12 +212,12 @@ IPCCommandResult NetWDCommandDevice::Open(const OpenRequest& request)
   return Device::Open(request);
 }
 
-IPCCommandResult NetWDCommandDevice::Close(u32 fd)
+std::optional<IPCReply> NetWDCommandDevice::Close(u32 fd)
 {
   if (m_ipc_owner_fd < 0 || fd != u32(m_ipc_owner_fd))
   {
     ERROR_LOG_FMT(IOS_NET, "Invalid close attempt.");
-    return GetDefaultReply(u32(ResultCode::InvalidFd));
+    return IPCReply(u32(ResultCode::InvalidFd));
   }
 
   INFO_LOG_FMT(IOS_NET, "Closing and resetting status to Idle");
@@ -228,11 +228,11 @@ IPCCommandResult NetWDCommandDevice::Close(u32 fd)
   return Device::Close(fd);
 }
 
-IPCCommandResult NetWDCommandDevice::SetLinkState(const IOCtlVRequest& request)
+IPCReply NetWDCommandDevice::SetLinkState(const IOCtlVRequest& request)
 {
   const auto* vector = request.GetVector(0);
   if (!vector || vector->address == 0)
-    return GetDefaultReply(u32(ResultCode::IllegalParameter));
+    return IPCReply(u32(ResultCode::IllegalParameter));
 
   const u32 state = Memory::Read_U32(vector->address);
   INFO_LOG_FMT(IOS_NET, "WD_SetLinkState called (state={}, mode={})", state, m_mode);
@@ -240,7 +240,7 @@ IPCCommandResult NetWDCommandDevice::SetLinkState(const IOCtlVRequest& request)
   if (state == 0)
   {
     if (!WD::IsValidMode(m_mode))
-      return GetDefaultReply(u32(ResultCode::UnavailableCommand));
+      return IPCReply(u32(ResultCode::UnavailableCommand));
 
     INFO_LOG_FMT(IOS_NET, "WD_SetLinkState: setting target status to 1 (Idle)");
     m_target_status = Status::Idle;
@@ -248,37 +248,37 @@ IPCCommandResult NetWDCommandDevice::SetLinkState(const IOCtlVRequest& request)
   else
   {
     if (state != 1)
-      return GetDefaultReply(u32(ResultCode::IllegalParameter));
+      return IPCReply(u32(ResultCode::IllegalParameter));
 
     if (!WD::IsValidMode(m_mode))
-      return GetDefaultReply(u32(ResultCode::UnavailableCommand));
+      return IPCReply(u32(ResultCode::UnavailableCommand));
 
     const auto target_status = GetTargetStatusForMode(m_mode);
     if (m_status != target_status && m_info.enabled_channels == 0)
-      return GetDefaultReply(u32(ResultCode::UnavailableCommand));
+      return IPCReply(u32(ResultCode::UnavailableCommand));
 
     INFO_LOG_FMT(IOS_NET, "WD_SetLinkState: setting target status to {}", target_status);
     m_target_status = target_status;
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult NetWDCommandDevice::GetLinkState(const IOCtlVRequest& request) const
+IPCReply NetWDCommandDevice::GetLinkState(const IOCtlVRequest& request) const
 {
   INFO_LOG_FMT(IOS_NET, "WD_GetLinkState called (status={}, mode={})", m_status, m_mode);
   if (!WD::IsValidMode(m_mode))
-    return GetDefaultReply(u32(ResultCode::UnavailableCommand));
+    return IPCReply(u32(ResultCode::UnavailableCommand));
 
   // Contrary to what the name of the ioctl suggests, this returns a boolean, not the current state.
-  return GetDefaultReply(u32(m_status == GetTargetStatusForMode(m_mode)));
+  return IPCReply(u32(m_status == GetTargetStatusForMode(m_mode)));
 }
 
-IPCCommandResult NetWDCommandDevice::Disassociate(const IOCtlVRequest& request)
+IPCReply NetWDCommandDevice::Disassociate(const IOCtlVRequest& request)
 {
   const auto* vector = request.GetVector(0);
   if (!vector || vector->address == 0)
-    return GetDefaultReply(u32(ResultCode::IllegalParameter));
+    return IPCReply(u32(ResultCode::IllegalParameter));
 
   Common::MACAddress mac;
   Memory::CopyFromEmu(mac.data(), vector->address, mac.size());
@@ -289,7 +289,7 @@ IPCCommandResult NetWDCommandDevice::Disassociate(const IOCtlVRequest& request)
       m_mode != WD::Mode::Unknown6)
   {
     ERROR_LOG_FMT(IOS_NET, "WD_Disassociate: cannot disassociate in mode {}", m_mode);
-    return GetDefaultReply(u32(ResultCode::UnavailableCommand));
+    return IPCReply(u32(ResultCode::UnavailableCommand));
   }
 
   const auto target_status = GetTargetStatusForMode(m_mode);
@@ -297,31 +297,31 @@ IPCCommandResult NetWDCommandDevice::Disassociate(const IOCtlVRequest& request)
   {
     ERROR_LOG_FMT(IOS_NET, "WD_Disassociate: cannot disassociate in status {} (target {})",
                   m_status, target_status);
-    return GetDefaultReply(u32(ResultCode::UnavailableCommand));
+    return IPCReply(u32(ResultCode::UnavailableCommand));
   }
 
   // TODO: Check the input MAC address and only return 0x80008001 if it is unknown.
-  return GetDefaultReply(u32(ResultCode::IllegalParameter));
+  return IPCReply(u32(ResultCode::IllegalParameter));
 }
 
-IPCCommandResult NetWDCommandDevice::GetInfo(const IOCtlVRequest& request) const
+IPCReply NetWDCommandDevice::GetInfo(const IOCtlVRequest& request) const
 {
   const auto* vector = request.GetVector(0);
   if (!vector || vector->address == 0)
-    return GetDefaultReply(u32(ResultCode::IllegalParameter));
+    return IPCReply(u32(ResultCode::IllegalParameter));
 
   Memory::CopyToEmu(vector->address, &m_info, sizeof(m_info));
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult NetWDCommandDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> NetWDCommandDevice::IOCtlV(const IOCtlVRequest& request)
 {
   switch (request.request)
   {
   case IOCTLV_WD_INVALID:
-    return GetDefaultReply(u32(ResultCode::UnavailableCommand));
+    return IPCReply(u32(ResultCode::UnavailableCommand));
   case IOCTLV_WD_GET_MODE:
-    return GetDefaultReply(s32(m_mode));
+    return IPCReply(s32(m_mode));
   case IOCTLV_WD_SET_LINKSTATE:
     return SetLinkState(request);
   case IOCTLV_WD_GET_LINKSTATE:
@@ -361,11 +361,11 @@ IPCCommandResult NetWDCommandDevice::IOCtlV(const IOCtlVRequest& request)
 
   case IOCTLV_WD_RECV_FRAME:
     m_recv_frame_requests.emplace_back(request.address);
-    return GetNoReply();
+    return std::nullopt;
 
   case IOCTLV_WD_RECV_NOTIFICATION:
     m_recv_notification_requests.emplace_back(request.address);
-    return GetNoReply();
+    return std::nullopt;
 
   case IOCTLV_WD_SET_CONFIG:
   case IOCTLV_WD_GET_CONFIG:
@@ -382,6 +382,6 @@ IPCCommandResult NetWDCommandDevice::IOCtlV(const IOCtlVRequest& request)
     request.Dump(GetDeviceName(), Common::Log::IOS_NET, Common::Log::LWARNING);
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/Network/WD/Command.h b/Source/Core/Core/IOS/Network/WD/Command.h
index 7e2f5cd2b5..8d89a16058 100644
--- a/Source/Core/Core/IOS/Network/WD/Command.h
+++ b/Source/Core/Core/IOS/Network/WD/Command.h
@@ -52,9 +52,9 @@ public:
 
   NetWDCommandDevice(Kernel& ios, const std::string& device_name);
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult Close(u32 fd) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Close(u32 fd) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
   void Update() override;
   bool IsOpened() const override { return true; }
   void DoState(PointerWrap& p) override;
@@ -153,10 +153,10 @@ private:
   void HandleStateChange();
   static Status GetTargetStatusForMode(WD::Mode mode);
 
-  IPCCommandResult SetLinkState(const IOCtlVRequest& request);
-  IPCCommandResult GetLinkState(const IOCtlVRequest& request) const;
-  IPCCommandResult Disassociate(const IOCtlVRequest& request);
-  IPCCommandResult GetInfo(const IOCtlVRequest& request) const;
+  IPCReply SetLinkState(const IOCtlVRequest& request);
+  IPCReply GetLinkState(const IOCtlVRequest& request) const;
+  IPCReply Disassociate(const IOCtlVRequest& request);
+  IPCReply GetInfo(const IOCtlVRequest& request) const;
 
   s32 m_ipc_owner_fd = -1;
   WD::Mode m_mode = WD::Mode::NotInitialized;
diff --git a/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp b/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp
index 45edf58ad0..122b5f6f71 100644
--- a/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp
+++ b/Source/Core/Core/IOS/SDIO/SDIOSlot0.cpp
@@ -79,17 +79,17 @@ void SDIOSlot0Device::OpenInternal()
   }
 }
 
-IPCCommandResult SDIOSlot0Device::Open(const OpenRequest& request)
+std::optional<IPCReply> SDIOSlot0Device::Open(const OpenRequest& request)
 {
   OpenInternal();
   m_registers.fill(0);
 
   m_is_active = true;
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::Close(u32 fd)
+std::optional<IPCReply> SDIOSlot0Device::Close(u32 fd)
 {
   m_card.Close();
   m_block_length = 0;
@@ -98,7 +98,7 @@ IPCCommandResult SDIOSlot0Device::Close(u32 fd)
   return Device::Close(fd);
 }
 
-IPCCommandResult SDIOSlot0Device::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> SDIOSlot0Device::IOCtl(const IOCtlRequest& request)
 {
   Memory::Memset(request.buffer_out, 0, request.buffer_out_size);
 
@@ -123,10 +123,10 @@ IPCCommandResult SDIOSlot0Device::IOCtl(const IOCtlRequest& request)
     break;
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> SDIOSlot0Device::IOCtlV(const IOCtlVRequest& request)
 {
   switch (request.request)
   {
@@ -137,7 +137,7 @@ IPCCommandResult SDIOSlot0Device::IOCtlV(const IOCtlVRequest& request)
     break;
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 s32 SDIOSlot0Device::ExecuteCommand(const Request& request, u32 buffer_in, u32 buffer_in_size,
@@ -325,7 +325,7 @@ s32 SDIOSlot0Device::ExecuteCommand(const Request& request, u32 buffer_in, u32 b
   return ret;
 }
 
-IPCCommandResult SDIOSlot0Device::WriteHCRegister(const IOCtlRequest& request)
+IPCReply SDIOSlot0Device::WriteHCRegister(const IOCtlRequest& request)
 {
   const u32 reg = Memory::Read_U32(request.buffer_in);
   const u32 val = Memory::Read_U32(request.buffer_in + 16);
@@ -335,7 +335,7 @@ IPCCommandResult SDIOSlot0Device::WriteHCRegister(const IOCtlRequest& request)
   if (reg >= m_registers.size())
   {
     WARN_LOG_FMT(IOS_SD, "IOCTL_WRITEHCR out of range");
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   }
 
   if ((reg == HCR_CLOCKCONTROL) && (val & 1))
@@ -354,17 +354,17 @@ IPCCommandResult SDIOSlot0Device::WriteHCRegister(const IOCtlRequest& request)
     m_registers[reg] = val;
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::ReadHCRegister(const IOCtlRequest& request)
+IPCReply SDIOSlot0Device::ReadHCRegister(const IOCtlRequest& request)
 {
   const u32 reg = Memory::Read_U32(request.buffer_in);
 
   if (reg >= m_registers.size())
   {
     WARN_LOG_FMT(IOS_SD, "IOCTL_READHCR out of range");
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   }
 
   const u32 val = m_registers[reg];
@@ -372,20 +372,20 @@ IPCCommandResult SDIOSlot0Device::ReadHCRegister(const IOCtlRequest& request)
 
   // Just reading the register
   Memory::Write_U32(val, request.buffer_out);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::ResetCard(const IOCtlRequest& request)
+IPCReply SDIOSlot0Device::ResetCard(const IOCtlRequest& request)
 {
   INFO_LOG_FMT(IOS_SD, "IOCTL_RESETCARD");
 
   // Returns 16bit RCA and 16bit 0s (meaning success)
   Memory::Write_U32(m_status, request.buffer_out);
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::SetClk(const IOCtlRequest& request)
+IPCReply SDIOSlot0Device::SetClk(const IOCtlRequest& request)
 {
   INFO_LOG_FMT(IOS_SD, "IOCTL_SETCLK");
 
@@ -395,10 +395,10 @@ IPCCommandResult SDIOSlot0Device::SetClk(const IOCtlRequest& request)
   if (clock != 1)
     INFO_LOG_FMT(IOS_SD, "Setting to {}, interesting", clock);
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::SendCommand(const IOCtlRequest& request)
+std::optional<IPCReply> SDIOSlot0Device::SendCommand(const IOCtlRequest& request)
 {
   INFO_LOG_FMT(IOS_SD, "IOCTL_SENDCMD {:x} IPC:{:08x}", Memory::Read_U32(request.buffer_in),
                request.address);
@@ -410,13 +410,13 @@ IPCCommandResult SDIOSlot0Device::SendCommand(const IOCtlRequest& request)
   {
     // Check if the condition is already true
     EventNotify();
-    return GetNoReply();
+    return std::nullopt;
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::GetStatus(const IOCtlRequest& request)
+IPCReply SDIOSlot0Device::GetStatus(const IOCtlRequest& request)
 {
   // Since IOS does the SD initialization itself, we just say we're always initialized.
   if (m_card)
@@ -450,19 +450,19 @@ IPCCommandResult SDIOSlot0Device::GetStatus(const IOCtlRequest& request)
                (status & CARD_INITIALIZED) ? " and initialized" : "");
 
   Memory::Write_U32(status, request.buffer_out);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::GetOCRegister(const IOCtlRequest& request)
+IPCReply SDIOSlot0Device::GetOCRegister(const IOCtlRequest& request)
 {
   const u32 ocr = GetOCRegister();
   INFO_LOG_FMT(IOS_SD, "IOCTL_GETOCR. Replying with ocr {:x}", ocr);
   Memory::Write_U32(ocr, request.buffer_out);
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult SDIOSlot0Device::SendCommand(const IOCtlVRequest& request)
+IPCReply SDIOSlot0Device::SendCommand(const IOCtlVRequest& request)
 {
   DEBUG_LOG_FMT(IOS_SD, "IOCTLV_SENDCMD {:#010x}", Memory::Read_U32(request.in_vectors[0].address));
   Memory::Memset(request.io_vectors[0].address, 0, request.io_vectors[0].size);
@@ -472,7 +472,7 @@ IPCCommandResult SDIOSlot0Device::SendCommand(const IOCtlVRequest& request)
                      request.in_vectors[1].address, request.in_vectors[1].size,
                      request.io_vectors[0].address, request.io_vectors[0].size);
 
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
 u32 SDIOSlot0Device::GetOCRegister() const
diff --git a/Source/Core/Core/IOS/SDIO/SDIOSlot0.h b/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
index 2245e1e2af..6f4debeb95 100644
--- a/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
+++ b/Source/Core/Core/IOS/SDIO/SDIOSlot0.h
@@ -26,10 +26,10 @@ public:
 
   void DoState(PointerWrap& p) override;
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult Close(u32 fd) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Close(u32 fd) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   void EventNotify();
 
@@ -125,15 +125,15 @@ private:
     Request request;
   };
 
-  IPCCommandResult WriteHCRegister(const IOCtlRequest& request);
-  IPCCommandResult ReadHCRegister(const IOCtlRequest& request);
-  IPCCommandResult ResetCard(const IOCtlRequest& request);
-  IPCCommandResult SetClk(const IOCtlRequest& request);
-  IPCCommandResult SendCommand(const IOCtlRequest& request);
-  IPCCommandResult GetStatus(const IOCtlRequest& request);
-  IPCCommandResult GetOCRegister(const IOCtlRequest& request);
+  IPCReply WriteHCRegister(const IOCtlRequest& request);
+  IPCReply ReadHCRegister(const IOCtlRequest& request);
+  IPCReply ResetCard(const IOCtlRequest& request);
+  IPCReply SetClk(const IOCtlRequest& request);
+  std::optional<IPCReply> SendCommand(const IOCtlRequest& request);
+  IPCReply GetStatus(const IOCtlRequest& request);
+  IPCReply GetOCRegister(const IOCtlRequest& request);
 
-  IPCCommandResult SendCommand(const IOCtlVRequest& request);
+  IPCReply SendCommand(const IOCtlVRequest& request);
 
   s32 ExecuteCommand(const Request& request, u32 buffer_in, u32 buffer_in_size, u32 rw_buffer,
                      u32 rw_buffer_size, u32 buffer_out, u32 buffer_out_size);
diff --git a/Source/Core/Core/IOS/STM/STM.cpp b/Source/Core/Core/IOS/STM/STM.cpp
index b310b8c54d..7d54008ef4 100644
--- a/Source/Core/Core/IOS/STM/STM.cpp
+++ b/Source/Core/Core/IOS/STM/STM.cpp
@@ -16,7 +16,7 @@ namespace IOS::HLE
 {
 static std::unique_ptr<IOCtlRequest> s_event_hook_request;
 
-IPCCommandResult STMImmediateDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> STMImmediateDevice::IOCtl(const IOCtlRequest& request)
 {
   s32 return_value = IPC_SUCCESS;
   switch (request.request)
@@ -59,7 +59,7 @@ IPCCommandResult STMImmediateDevice::IOCtl(const IOCtlRequest& request)
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_STM);
   }
 
-  return GetDefaultReply(return_value);
+  return IPCReply(return_value);
 }
 
 STMEventHookDevice::~STMEventHookDevice()
@@ -67,17 +67,17 @@ STMEventHookDevice::~STMEventHookDevice()
   s_event_hook_request.reset();
 }
 
-IPCCommandResult STMEventHookDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> STMEventHookDevice::IOCtl(const IOCtlRequest& request)
 {
   if (request.request != IOCTL_STM_EVENTHOOK)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   if (s_event_hook_request)
-    return GetDefaultReply(IPC_EEXIST);
+    return IPCReply(IPC_EEXIST);
 
   // IOCTL_STM_EVENTHOOK waits until the reset button or power button is pressed.
   s_event_hook_request = std::make_unique<IOCtlRequest>(request.address);
-  return GetNoReply();
+  return std::nullopt;
 }
 
 void STMEventHookDevice::DoState(PointerWrap& p)
diff --git a/Source/Core/Core/IOS/STM/STM.h b/Source/Core/Core/IOS/STM/STM.h
index 4432cce177..ba644f9c6d 100644
--- a/Source/Core/Core/IOS/STM/STM.h
+++ b/Source/Core/Core/IOS/STM/STM.h
@@ -43,7 +43,7 @@ class STMImmediateDevice final : public Device
 {
 public:
   using Device::Device;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
 };
 
 // The /dev/stm/eventhook
@@ -52,7 +52,7 @@ class STMEventHookDevice final : public Device
 public:
   using Device::Device;
   ~STMEventHookDevice() override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
   void DoState(PointerWrap& p) override;
 
   bool HasHookInstalled() const;
diff --git a/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.cpp b/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.cpp
index 49c81a2e32..9958030fbd 100644
--- a/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.cpp
+++ b/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.cpp
@@ -127,7 +127,7 @@ bool BluetoothEmuDevice::RemoteDisconnect(const bdaddr_t& address)
   return SendEventDisconnect(GetConnectionHandle(address), 0x13);
 }
 
-IPCCommandResult BluetoothEmuDevice::Close(u32 fd)
+std::optional<IPCReply> BluetoothEmuDevice::Close(u32 fd)
 {
   // Clean up state
   m_scan_enable = 0;
@@ -139,7 +139,7 @@ IPCCommandResult BluetoothEmuDevice::Close(u32 fd)
   return Device::Close(fd);
 }
 
-IPCCommandResult BluetoothEmuDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> BluetoothEmuDevice::IOCtlV(const IOCtlVRequest& request)
 {
   bool send_reply = true;
   switch (request.request)
@@ -204,7 +204,9 @@ IPCCommandResult BluetoothEmuDevice::IOCtlV(const IOCtlVRequest& request)
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_WIIMOTE);
   }
 
-  return send_reply ? GetDefaultReply(IPC_SUCCESS) : GetNoReply();
+  if (!send_reply)
+    return std::nullopt;
+  return IPCReply(IPC_SUCCESS);
 }
 
 // Here we handle the USB::IOCTLV_USBV0_BLKMSG Ioctlv
diff --git a/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.h b/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.h
index ec236a013b..eb2e70625c 100644
--- a/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.h
+++ b/Source/Core/Core/IOS/USB/Bluetooth/BTEmu.h
@@ -44,8 +44,8 @@ public:
 
   virtual ~BluetoothEmuDevice();
 
-  IPCCommandResult Close(u32 fd) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Close(u32 fd) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   void Update() override;
 
diff --git a/Source/Core/Core/IOS/USB/Bluetooth/BTReal.cpp b/Source/Core/Core/IOS/USB/Bluetooth/BTReal.cpp
index 5a50bcafcf..968c3f8ada 100644
--- a/Source/Core/Core/IOS/USB/Bluetooth/BTReal.cpp
+++ b/Source/Core/Core/IOS/USB/Bluetooth/BTReal.cpp
@@ -77,10 +77,10 @@ BluetoothRealDevice::~BluetoothRealDevice()
   SaveLinkKeys();
 }
 
-IPCCommandResult BluetoothRealDevice::Open(const OpenRequest& request)
+std::optional<IPCReply> BluetoothRealDevice::Open(const OpenRequest& request)
 {
   if (!m_context.IsValid())
-    return GetDefaultReply(IPC_EACCES);
+    return IPCReply(IPC_EACCES);
 
   m_last_open_error.clear();
   m_context.GetDeviceList([this](libusb_device* device) {
@@ -132,13 +132,13 @@ IPCCommandResult BluetoothRealDevice::Open(const OpenRequest& request)
           m_last_open_error);
     }
     Core::QueueHostJob(Core::Stop);
-    return GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
   }
 
   return Device::Open(request);
 }
 
-IPCCommandResult BluetoothRealDevice::Close(u32 fd)
+std::optional<IPCReply> BluetoothRealDevice::Close(u32 fd)
 {
   if (m_handle)
   {
@@ -151,7 +151,7 @@ IPCCommandResult BluetoothRealDevice::Close(u32 fd)
   return Device::Close(fd);
 }
 
-IPCCommandResult BluetoothRealDevice::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> BluetoothRealDevice::IOCtlV(const IOCtlVRequest& request)
 {
   if (!m_is_wii_bt_module && m_need_reset_keys.TestAndClear())
   {
@@ -173,13 +173,13 @@ IPCCommandResult BluetoothRealDevice::IOCtlV(const IOCtlVRequest& request)
     if (opcode == HCI_CMD_READ_BUFFER_SIZE)
     {
       m_fake_read_buffer_size_reply.Set();
-      return GetNoReply();
+      return std::nullopt;
     }
     if (!m_is_wii_bt_module && (opcode == 0xFC4C || opcode == 0xFC4F))
     {
       m_fake_vendor_command_reply.Set();
       m_fake_vendor_command_reply_opcode = opcode;
-      return GetNoReply();
+      return std::nullopt;
     }
     if (opcode == HCI_CMD_DELETE_STORED_LINK_KEY)
     {
@@ -218,23 +218,23 @@ IPCCommandResult BluetoothRealDevice::IOCtlV(const IOCtlVRequest& request)
       {
         Core::DisplayMessage("Scanning for Wii Remotes", 2000);
         FakeSyncButtonPressedEvent(*cmd);
-        return GetNoReply();
+        return std::nullopt;
       }
       if (m_sync_button_state == SyncButtonState::LongPressed)
       {
         Core::DisplayMessage("Reset saved Wii Remote pairings", 2000);
         FakeSyncButtonHeldEvent(*cmd);
-        return GetNoReply();
+        return std::nullopt;
       }
       if (m_fake_read_buffer_size_reply.TestAndClear())
       {
         FakeReadBufferSizeReply(*cmd);
-        return GetNoReply();
+        return std::nullopt;
       }
       if (m_fake_vendor_command_reply.TestAndClear())
       {
         FakeVendorCommandReply(*cmd);
-        return GetNoReply();
+        return std::nullopt;
       }
     }
     auto buffer = cmd->MakeBuffer(cmd->length);
@@ -258,7 +258,7 @@ IPCCommandResult BluetoothRealDevice::IOCtlV(const IOCtlVRequest& request)
   }
   }
   // Replies are generated inside of the message handlers (and asynchronously).
-  return GetNoReply();
+  return std::nullopt;
 }
 
 static bool s_has_shown_savestate_warning = false;
diff --git a/Source/Core/Core/IOS/USB/Bluetooth/BTReal.h b/Source/Core/Core/IOS/USB/Bluetooth/BTReal.h
index d65a26f023..cb927ac5f6 100644
--- a/Source/Core/Core/IOS/USB/Bluetooth/BTReal.h
+++ b/Source/Core/Core/IOS/USB/Bluetooth/BTReal.h
@@ -46,9 +46,9 @@ public:
   BluetoothRealDevice(Kernel& ios, const std::string& device_name);
   ~BluetoothRealDevice() override;
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult Close(u32 fd) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Close(u32 fd) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   void DoState(PointerWrap& p) override;
   void UpdateSyncButtonState(bool is_held) override;
diff --git a/Source/Core/Core/IOS/USB/Bluetooth/BTStub.cpp b/Source/Core/Core/IOS/USB/Bluetooth/BTStub.cpp
index b66a2a26c7..af6c6f2672 100644
--- a/Source/Core/Core/IOS/USB/Bluetooth/BTStub.cpp
+++ b/Source/Core/Core/IOS/USB/Bluetooth/BTStub.cpp
@@ -10,11 +10,11 @@
 
 namespace IOS::HLE
 {
-IPCCommandResult BluetoothStubDevice::Open(const OpenRequest& request)
+std::optional<IPCReply> BluetoothStubDevice::Open(const OpenRequest& request)
 {
   PanicAlertFmtT("Bluetooth passthrough mode is enabled, but Dolphin was built without libusb."
                  " Passthrough mode cannot be used.");
-  return GetDefaultReply(IPC_ENOENT);
+  return IPCReply(IPC_ENOENT);
 }
 
 void BluetoothStubDevice::DoState(PointerWrap& p)
diff --git a/Source/Core/Core/IOS/USB/Bluetooth/BTStub.h b/Source/Core/Core/IOS/USB/Bluetooth/BTStub.h
index 5a422b3936..32737b841e 100644
--- a/Source/Core/Core/IOS/USB/Bluetooth/BTStub.h
+++ b/Source/Core/Core/IOS/USB/Bluetooth/BTStub.h
@@ -18,7 +18,7 @@ class BluetoothStubDevice final : public BluetoothBaseDevice
 {
 public:
   using BluetoothBaseDevice::BluetoothBaseDevice;
-  IPCCommandResult Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
   void DoState(PointerWrap& p) override;
 };
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/USB/Host.cpp b/Source/Core/Core/IOS/USB/Host.cpp
index 6d082c1f93..416b1e34a5 100644
--- a/Source/Core/Core/IOS/USB/Host.cpp
+++ b/Source/Core/Core/IOS/USB/Host.cpp
@@ -33,7 +33,7 @@ USBHost::USBHost(Kernel& ios, const std::string& device_name) : Device(ios, devi
 
 USBHost::~USBHost() = default;
 
-IPCCommandResult USBHost::Open(const OpenRequest& request)
+std::optional<IPCReply> USBHost::Open(const OpenRequest& request)
 {
   if (!m_has_initialised && !Core::WantsDeterminism())
   {
@@ -43,7 +43,7 @@ IPCCommandResult USBHost::Open(const OpenRequest& request)
     GetScanThread().WaitForFirstScan();
     m_has_initialised = true;
   }
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 void USBHost::UpdateWantDeterminism(const bool new_want_determinism)
@@ -213,18 +213,18 @@ void USBHost::ScanThread::Stop()
   m_host->DispatchHooks(hooks);
 }
 
-IPCCommandResult USBHost::HandleTransfer(std::shared_ptr<USB::Device> device, u32 request,
-                                         std::function<s32()> submit) const
+std::optional<IPCReply> USBHost::HandleTransfer(std::shared_ptr<USB::Device> device, u32 request,
+                                                std::function<s32()> submit) const
 {
   if (!device)
-    return GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
 
   const s32 ret = submit();
   if (ret == IPC_SUCCESS)
-    return GetNoReply();
+    return std::nullopt;
 
   ERROR_LOG_FMT(IOS_USB, "[{:04x}:{:04x}] Failed to submit transfer (request {}): {}",
                 device->GetVid(), device->GetPid(), request, device->GetErrorName(ret));
-  return GetDefaultReply(ret <= 0 ? ret : IPC_EINVAL);
+  return IPCReply(ret <= 0 ? ret : IPC_EINVAL);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/USB/Host.h b/Source/Core/Core/IOS/USB/Host.h
index cb02961b9a..f995e0f57c 100644
--- a/Source/Core/Core/IOS/USB/Host.h
+++ b/Source/Core/Core/IOS/USB/Host.h
@@ -33,7 +33,7 @@ public:
   USBHost(Kernel& ios, const std::string& device_name);
   virtual ~USBHost();
 
-  IPCCommandResult Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
 
   void UpdateWantDeterminism(bool new_want_determinism) override;
   void DoState(PointerWrap& p) override;
@@ -72,8 +72,8 @@ protected:
   virtual bool ShouldAddDevice(const USB::Device& device) const;
   virtual ScanThread& GetScanThread() = 0;
 
-  IPCCommandResult HandleTransfer(std::shared_ptr<USB::Device> device, u32 request,
-                                  std::function<s32()> submit) const;
+  std::optional<IPCReply> HandleTransfer(std::shared_ptr<USB::Device> device, u32 request,
+                                         std::function<s32()> submit) const;
 
 private:
   bool AddDevice(std::unique_ptr<USB::Device> device);
diff --git a/Source/Core/Core/IOS/USB/OH0/OH0.cpp b/Source/Core/Core/IOS/USB/OH0/OH0.cpp
index ef43b5d1ea..a74730e953 100644
--- a/Source/Core/Core/IOS/USB/OH0/OH0.cpp
+++ b/Source/Core/Core/IOS/USB/OH0/OH0.cpp
@@ -31,14 +31,14 @@ OH0::~OH0()
   m_scan_thread.Stop();
 }
 
-IPCCommandResult OH0::Open(const OpenRequest& request)
+std::optional<IPCReply> OH0::Open(const OpenRequest& request)
 {
   if (HasFeature(m_ios.GetVersion(), Feature::NewUSB))
-    return GetDefaultReply(IPC_EACCES);
+    return IPCReply(IPC_EACCES);
   return USBHost::Open(request);
 }
 
-IPCCommandResult OH0::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> OH0::IOCtl(const IOCtlRequest& request)
 {
   request.Log(GetDeviceName(), Common::Log::IOS_USB);
   switch (request.request)
@@ -48,11 +48,11 @@ IPCCommandResult OH0::IOCtl(const IOCtlRequest& request)
   case USB::IOCTL_USBV0_CANCEL_INSERT_HOOK:
     return CancelInsertionHook(request);
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 
-IPCCommandResult OH0::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> OH0::IOCtlV(const IOCtlVRequest& request)
 {
   INFO_LOG_FMT(IOS_USB, "/dev/usb/oh0 - IOCtlV {}", request.request);
   switch (request.request)
@@ -70,7 +70,7 @@ IPCCommandResult OH0::IOCtlV(const IOCtlVRequest& request)
   case USB::IOCTLV_USBV0_DEVINSERTHOOKID:
     return RegisterInsertionHookWithID(request);
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 
@@ -88,26 +88,26 @@ void OH0::DoState(PointerWrap& p)
   USBHost::DoState(p);
 }
 
-IPCCommandResult OH0::CancelInsertionHook(const IOCtlRequest& request)
+IPCReply OH0::CancelInsertionHook(const IOCtlRequest& request)
 {
   if (!request.buffer_in || request.buffer_in_size != 4)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   // IOS assigns random IDs, but ours are simply the VID + PID (see RegisterInsertionHookWithID)
   TriggerHook(m_insertion_hooks,
               {Memory::Read_U16(request.buffer_in), Memory::Read_U16(request.buffer_in + 2)},
               USB_ECANCELED);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult OH0::GetDeviceList(const IOCtlVRequest& request) const
+IPCReply OH0::GetDeviceList(const IOCtlVRequest& request) const
 {
   if (!request.HasNumberOfValidVectors(2, 2))
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   const u8 max_entries_count = Memory::Read_U8(request.in_vectors[0].address);
   if (request.io_vectors[1].size != max_entries_count * sizeof(DeviceEntry))
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   const u8 interface_class = Memory::Read_U8(request.in_vectors[1].address);
   u8 entries_count = 0;
@@ -126,91 +126,91 @@ IPCCommandResult OH0::GetDeviceList(const IOCtlVRequest& request) const
     Memory::CopyToEmu(request.io_vectors[1].address + 8 * entries_count++, &entry, 8);
   }
   Memory::Write_U8(entries_count, request.io_vectors[0].address);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult OH0::GetRhDesca(const IOCtlRequest& request) const
+IPCReply OH0::GetRhDesca(const IOCtlRequest& request) const
 {
   if (!request.buffer_out || request.buffer_out_size != 4)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   // Based on a hardware test, this ioctl seems to return a constant value
   Memory::Write_U32(0x02000302, request.buffer_out);
   request.Dump(GetDeviceName(), Common::Log::IOS_USB, Common::Log::LWARNING);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult OH0::GetRhPortStatus(const IOCtlVRequest& request) const
+IPCReply OH0::GetRhPortStatus(const IOCtlVRequest& request) const
 {
   if (!request.HasNumberOfValidVectors(1, 1))
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   ERROR_LOG_FMT(IOS_USB, "Unimplemented IOCtlV: IOCTLV_USBV0_GETRHPORTSTATUS");
   request.Dump(GetDeviceName(), Common::Log::IOS_USB, Common::Log::LERROR);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult OH0::SetRhPortStatus(const IOCtlVRequest& request)
+IPCReply OH0::SetRhPortStatus(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 0))
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   ERROR_LOG_FMT(IOS_USB, "Unimplemented IOCtlV: IOCTLV_USBV0_SETRHPORTSTATUS");
   request.Dump(GetDeviceName(), Common::Log::IOS_USB, Common::Log::LERROR);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult OH0::RegisterRemovalHook(const u64 device_id, const IOCtlRequest& request)
+std::optional<IPCReply> OH0::RegisterRemovalHook(const u64 device_id, const IOCtlRequest& request)
 {
   std::lock_guard lock{m_hooks_mutex};
   // IOS only allows a single device removal hook.
   if (m_removal_hooks.find(device_id) != m_removal_hooks.end())
-    return GetDefaultReply(IPC_EEXIST);
+    return IPCReply(IPC_EEXIST);
   m_removal_hooks.insert({device_id, request.address});
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult OH0::RegisterInsertionHook(const IOCtlVRequest& request)
+std::optional<IPCReply> OH0::RegisterInsertionHook(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(2, 0))
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   const u16 vid = Memory::Read_U16(request.in_vectors[0].address);
   const u16 pid = Memory::Read_U16(request.in_vectors[1].address);
   if (HasDeviceWithVidPid(vid, pid))
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
 
   std::lock_guard lock{m_hooks_mutex};
   // TODO: figure out whether IOS allows more than one hook.
   m_insertion_hooks[{vid, pid}] = request.address;
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult OH0::RegisterInsertionHookWithID(const IOCtlVRequest& request)
+std::optional<IPCReply> OH0::RegisterInsertionHookWithID(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(3, 1))
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   std::lock_guard lock{m_hooks_mutex};
   const u16 vid = Memory::Read_U16(request.in_vectors[0].address);
   const u16 pid = Memory::Read_U16(request.in_vectors[1].address);
   const bool trigger_only_for_new_device = Memory::Read_U8(request.in_vectors[2].address) == 1;
   if (!trigger_only_for_new_device && HasDeviceWithVidPid(vid, pid))
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   // TODO: figure out whether IOS allows more than one hook.
   m_insertion_hooks.insert({{vid, pid}, request.address});
   // The output vector is overwritten with an ID to use with ioctl 31 for cancelling the hook.
   Memory::Write_U32(vid << 16 | pid, request.io_vectors[0].address);
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult OH0::RegisterClassChangeHook(const IOCtlVRequest& request)
+std::optional<IPCReply> OH0::RegisterClassChangeHook(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 0))
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   WARN_LOG_FMT(IOS_USB, "Unimplemented IOCtlV: USB::IOCTLV_USBV0_DEVICECLASSCHANGE (no reply)");
   request.Dump(GetDeviceName(), Common::Log::IOS_USB, Common::Log::LWARNING);
-  return GetNoReply();
+  return std::nullopt;
 }
 
 bool OH0::HasDeviceWithVidPid(const u16 vid, const u16 pid) const
@@ -270,11 +270,11 @@ void OH0::DeviceClose(const u64 device_id)
   m_opened_devices.erase(device_id);
 }
 
-IPCCommandResult OH0::DeviceIOCtl(const u64 device_id, const IOCtlRequest& request)
+std::optional<IPCReply> OH0::DeviceIOCtl(const u64 device_id, const IOCtlRequest& request)
 {
   const auto device = GetDeviceById(device_id);
   if (!device)
-    return GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
 
   switch (request.request)
   {
@@ -283,20 +283,20 @@ IPCCommandResult OH0::DeviceIOCtl(const u64 device_id, const IOCtlRequest& reque
   case USB::IOCTL_USBV0_SUSPENDDEV:
   case USB::IOCTL_USBV0_RESUMEDEV:
     // Unimplemented because libusb doesn't do power management.
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   case USB::IOCTL_USBV0_RESET_DEVICE:
     TriggerHook(m_removal_hooks, device_id, IPC_SUCCESS);
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 
-IPCCommandResult OH0::DeviceIOCtlV(const u64 device_id, const IOCtlVRequest& request)
+std::optional<IPCReply> OH0::DeviceIOCtlV(const u64 device_id, const IOCtlVRequest& request)
 {
   const auto device = GetDeviceById(device_id);
   if (!device)
-    return GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
 
   switch (request.request)
   {
@@ -309,9 +309,9 @@ IPCCommandResult OH0::DeviceIOCtlV(const u64 device_id, const IOCtlVRequest& req
                           [&, this]() { return SubmitTransfer(*device, request); });
   case USB::IOCTLV_USBV0_UNKNOWN_32:
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_USB);
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 
diff --git a/Source/Core/Core/IOS/USB/OH0/OH0.h b/Source/Core/Core/IOS/USB/OH0/OH0.h
index 4e50a06c99..61f94d94c8 100644
--- a/Source/Core/Core/IOS/USB/OH0/OH0.h
+++ b/Source/Core/Core/IOS/USB/OH0/OH0.h
@@ -37,27 +37,27 @@ public:
   OH0(Kernel& ios, const std::string& device_name);
   ~OH0() override;
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
   std::pair<ReturnCode, u64> DeviceOpen(u16 vid, u16 pid);
   void DeviceClose(u64 device_id);
-  IPCCommandResult DeviceIOCtl(u64 device_id, const IOCtlRequest& request);
-  IPCCommandResult DeviceIOCtlV(u64 device_id, const IOCtlVRequest& request);
+  std::optional<IPCReply> DeviceIOCtl(u64 device_id, const IOCtlRequest& request);
+  std::optional<IPCReply> DeviceIOCtlV(u64 device_id, const IOCtlVRequest& request);
 
   void DoState(PointerWrap& p) override;
 
 private:
-  IPCCommandResult CancelInsertionHook(const IOCtlRequest& request);
-  IPCCommandResult GetDeviceList(const IOCtlVRequest& request) const;
-  IPCCommandResult GetRhDesca(const IOCtlRequest& request) const;
-  IPCCommandResult GetRhPortStatus(const IOCtlVRequest& request) const;
-  IPCCommandResult SetRhPortStatus(const IOCtlVRequest& request);
-  IPCCommandResult RegisterRemovalHook(u64 device_id, const IOCtlRequest& request);
-  IPCCommandResult RegisterInsertionHook(const IOCtlVRequest& request);
-  IPCCommandResult RegisterInsertionHookWithID(const IOCtlVRequest& request);
-  IPCCommandResult RegisterClassChangeHook(const IOCtlVRequest& request);
+  IPCReply CancelInsertionHook(const IOCtlRequest& request);
+  IPCReply GetDeviceList(const IOCtlVRequest& request) const;
+  IPCReply GetRhDesca(const IOCtlRequest& request) const;
+  IPCReply GetRhPortStatus(const IOCtlVRequest& request) const;
+  IPCReply SetRhPortStatus(const IOCtlVRequest& request);
+  std::optional<IPCReply> RegisterRemovalHook(u64 device_id, const IOCtlRequest& request);
+  std::optional<IPCReply> RegisterInsertionHook(const IOCtlVRequest& request);
+  std::optional<IPCReply> RegisterInsertionHookWithID(const IOCtlVRequest& request);
+  std::optional<IPCReply> RegisterClassChangeHook(const IOCtlVRequest& request);
   s32 SubmitTransfer(USB::Device& device, const IOCtlVRequest& request);
 
   bool HasDeviceWithVidPid(u16 vid, u16 pid) const;
diff --git a/Source/Core/Core/IOS/USB/OH0/OH0Device.cpp b/Source/Core/Core/IOS/USB/OH0/OH0Device.cpp
index 7b2e5605e0..17f516a34f 100644
--- a/Source/Core/Core/IOS/USB/OH0/OH0Device.cpp
+++ b/Source/Core/Core/IOS/USB/OH0/OH0Device.cpp
@@ -51,30 +51,30 @@ void OH0Device::DoState(PointerWrap& p)
   p.Do(m_device_id);
 }
 
-IPCCommandResult OH0Device::Open(const OpenRequest& request)
+std::optional<IPCReply> OH0Device::Open(const OpenRequest& request)
 {
   if (m_vid == 0 && m_pid == 0)
-    return GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
 
   m_oh0 = std::static_pointer_cast<OH0>(GetIOS()->GetDeviceByName("/dev/usb/oh0"));
 
   ReturnCode return_code;
   std::tie(return_code, m_device_id) = m_oh0->DeviceOpen(m_vid, m_pid);
-  return GetDefaultReply(return_code);
+  return IPCReply(return_code);
 }
 
-IPCCommandResult OH0Device::Close(u32 fd)
+std::optional<IPCReply> OH0Device::Close(u32 fd)
 {
   m_oh0->DeviceClose(m_device_id);
   return Device::Close(fd);
 }
 
-IPCCommandResult OH0Device::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> OH0Device::IOCtl(const IOCtlRequest& request)
 {
   return m_oh0->DeviceIOCtl(m_device_id, request);
 }
 
-IPCCommandResult OH0Device::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> OH0Device::IOCtlV(const IOCtlVRequest& request)
 {
   return m_oh0->DeviceIOCtlV(m_device_id, request);
 }
diff --git a/Source/Core/Core/IOS/USB/OH0/OH0Device.h b/Source/Core/Core/IOS/USB/OH0/OH0Device.h
index ce6469776c..c775414295 100644
--- a/Source/Core/Core/IOS/USB/OH0/OH0Device.h
+++ b/Source/Core/Core/IOS/USB/OH0/OH0Device.h
@@ -20,10 +20,10 @@ class OH0Device final : public Device
 public:
   OH0Device(Kernel& ios, const std::string& device_name);
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult Close(u32 fd) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Close(u32 fd) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
   void DoState(PointerWrap& p) override;
 
 private:
diff --git a/Source/Core/Core/IOS/USB/USBV5.cpp b/Source/Core/Core/IOS/USB/USBV5.cpp
index 8f0f419ede..23118cca97 100644
--- a/Source/Core/Core/IOS/USB/USBV5.cpp
+++ b/Source/Core/Core/IOS/USB/USBV5.cpp
@@ -113,10 +113,10 @@ USBV5ResourceManager::USBV5Device* USBV5ResourceManager::GetUSBV5Device(u32 in_b
   return usbv5_device;
 }
 
-IPCCommandResult USBV5ResourceManager::GetDeviceChange(const IOCtlRequest& request)
+std::optional<IPCReply> USBV5ResourceManager::GetDeviceChange(const IOCtlRequest& request)
 {
   if (request.buffer_out_size != 0x180 || m_devicechange_hook_request)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   std::lock_guard lk{m_devicechange_hook_address_mutex};
   m_devicechange_hook_request = std::make_unique<IOCtlRequest>(request.address);
@@ -126,28 +126,27 @@ IPCCommandResult USBV5ResourceManager::GetDeviceChange(const IOCtlRequest& reque
     TriggerDeviceChangeReply();
     m_devicechange_first_call = false;
   }
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult USBV5ResourceManager::SetAlternateSetting(USBV5Device& device,
-                                                           const IOCtlRequest& request)
+IPCReply USBV5ResourceManager::SetAlternateSetting(USBV5Device& device, const IOCtlRequest& request)
 {
   const auto host_device = GetDeviceById(device.host_id);
   if (!host_device->AttachAndChangeInterface(device.interface_number))
-    return GetDefaultReply(-1);
+    return IPCReply(-1);
 
   const u8 alt_setting = Memory::Read_U8(request.buffer_in + 2 * sizeof(s32));
 
   const bool success = host_device->SetAltSetting(alt_setting) == 0;
-  return GetDefaultReply(success ? IPC_SUCCESS : IPC_EINVAL);
+  return IPCReply(success ? IPC_SUCCESS : IPC_EINVAL);
 }
 
-IPCCommandResult USBV5ResourceManager::Shutdown(const IOCtlRequest& request)
+IPCReply USBV5ResourceManager::Shutdown(const IOCtlRequest& request)
 {
   if (request.buffer_in != 0 || request.buffer_in_size != 0 || request.buffer_out != 0 ||
       request.buffer_out_size != 0)
   {
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 
   std::lock_guard lk{m_devicechange_hook_address_mutex};
@@ -156,11 +155,10 @@ IPCCommandResult USBV5ResourceManager::Shutdown(const IOCtlRequest& request)
     m_ios.EnqueueIPCReply(*m_devicechange_hook_request, IPC_SUCCESS);
     m_devicechange_hook_request.reset();
   }
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult USBV5ResourceManager::SuspendResume(USBV5Device& device,
-                                                     const IOCtlRequest& request)
+IPCReply USBV5ResourceManager::SuspendResume(USBV5Device& device, const IOCtlRequest& request)
 {
   const auto host_device = GetDeviceById(device.host_id);
   const s32 resumed = Memory::Read_U32(request.buffer_in + 8);
@@ -169,19 +167,19 @@ IPCCommandResult USBV5ResourceManager::SuspendResume(USBV5Device& device,
   // platform-independant way (libusb does not support power management).
   INFO_LOG_FMT(IOS_USB, "[{:04x}:{:04x} {}] Received {} command", host_device->GetVid(),
                host_device->GetPid(), device.interface_number, resumed == 0 ? "suspend" : "resume");
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult USBV5ResourceManager::HandleDeviceIOCtl(const IOCtlRequest& request,
-                                                         Handler handler)
+std::optional<IPCReply> USBV5ResourceManager::HandleDeviceIOCtl(const IOCtlRequest& request,
+                                                                Handler handler)
 {
   if (request.buffer_in == 0 || request.buffer_in_size != 0x20)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   std::lock_guard lock{m_usbv5_devices_mutex};
   USBV5Device* device = GetUSBV5Device(request.buffer_in);
   if (!device)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   return handler(*device);
 }
 
diff --git a/Source/Core/Core/IOS/USB/USBV5.h b/Source/Core/Core/IOS/USB/USBV5.h
index 8575082650..3d20ee6261 100644
--- a/Source/Core/Core/IOS/USB/USBV5.h
+++ b/Source/Core/Core/IOS/USB/USBV5.h
@@ -68,8 +68,8 @@ class USBV5ResourceManager : public USBHost
 public:
   using USBHost::USBHost;
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override = 0;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override = 0;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override = 0;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override = 0;
 
   void DoState(PointerWrap& p) override;
 
@@ -77,13 +77,13 @@ protected:
   struct USBV5Device;
   USBV5Device* GetUSBV5Device(u32 in_buffer);
 
-  IPCCommandResult GetDeviceChange(const IOCtlRequest& request);
-  IPCCommandResult SetAlternateSetting(USBV5Device& device, const IOCtlRequest& request);
-  IPCCommandResult Shutdown(const IOCtlRequest& request);
-  IPCCommandResult SuspendResume(USBV5Device& device, const IOCtlRequest& request);
+  std::optional<IPCReply> GetDeviceChange(const IOCtlRequest& request);
+  IPCReply SetAlternateSetting(USBV5Device& device, const IOCtlRequest& request);
+  IPCReply Shutdown(const IOCtlRequest& request);
+  IPCReply SuspendResume(USBV5Device& device, const IOCtlRequest& request);
 
-  using Handler = std::function<IPCCommandResult(USBV5Device&)>;
-  IPCCommandResult HandleDeviceIOCtl(const IOCtlRequest& request, Handler handler);
+  using Handler = std::function<std::optional<IPCReply>(USBV5Device&)>;
+  std::optional<IPCReply> HandleDeviceIOCtl(const IOCtlRequest& request, Handler handler);
 
   void OnDeviceChange(ChangeEvent event, std::shared_ptr<USB::Device> device) override;
   void OnDeviceChangeEnd() override;
diff --git a/Source/Core/Core/IOS/USB/USB_HID/HIDv4.cpp b/Source/Core/Core/IOS/USB/USB_HID/HIDv4.cpp
index 8ed6a0a1d3..d8e8613814 100644
--- a/Source/Core/Core/IOS/USB/USB_HID/HIDv4.cpp
+++ b/Source/Core/Core/IOS/USB/USB_HID/HIDv4.cpp
@@ -31,20 +31,20 @@ USB_HIDv4::~USB_HIDv4()
   m_scan_thread.Stop();
 }
 
-IPCCommandResult USB_HIDv4::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> USB_HIDv4::IOCtl(const IOCtlRequest& request)
 {
   request.Log(GetDeviceName(), Common::Log::IOS_USB);
   switch (request.request)
   {
   case USB::IOCTL_USBV4_GETVERSION:
-    return GetDefaultReply(VERSION);
+    return IPCReply(VERSION);
   case USB::IOCTL_USBV4_GETDEVICECHANGE:
     return GetDeviceChange(request);
   case USB::IOCTL_USBV4_SHUTDOWN:
     return Shutdown(request);
   case USB::IOCTL_USBV4_SET_SUSPEND:
     // Not implemented in IOS
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   case USB::IOCTL_USBV4_CANCELINTERRUPT:
     return CancelInterrupt(request);
   case USB::IOCTL_USBV4_GET_US_STRING:
@@ -53,36 +53,36 @@ IPCCommandResult USB_HIDv4::IOCtl(const IOCtlRequest& request)
   case USB::IOCTL_USBV4_INTRMSG_OUT:
   {
     if (request.buffer_in == 0 || request.buffer_in_size != 32)
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
     const auto device = GetDeviceByIOSID(Memory::Read_U32(request.buffer_in + 16));
     if (!device->Attach())
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
     return HandleTransfer(device, request.request,
                           [&, this]() { return SubmitTransfer(*device, request); });
   }
   default:
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_USB);
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   }
 }
 
-IPCCommandResult USB_HIDv4::CancelInterrupt(const IOCtlRequest& request)
+IPCReply USB_HIDv4::CancelInterrupt(const IOCtlRequest& request)
 {
   if (request.buffer_in == 0 || request.buffer_in_size != 8)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   auto device = GetDeviceByIOSID(Memory::Read_U32(request.buffer_in));
   if (!device)
-    return GetDefaultReply(IPC_ENOENT);
+    return IPCReply(IPC_ENOENT);
   device->CancelTransfer(Memory::Read_U8(request.buffer_in + 4));
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult USB_HIDv4::GetDeviceChange(const IOCtlRequest& request)
+std::optional<IPCReply> USB_HIDv4::GetDeviceChange(const IOCtlRequest& request)
 {
   std::lock_guard lk{m_devicechange_hook_address_mutex};
   if (request.buffer_out == 0 || request.buffer_out_size != 0x600)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   m_devicechange_hook_request = std::make_unique<IOCtlRequest>(request.address);
   // On the first call, the reply is sent immediately (instead of on device insertion/removal)
@@ -91,10 +91,10 @@ IPCCommandResult USB_HIDv4::GetDeviceChange(const IOCtlRequest& request)
     TriggerDeviceChangeReply();
     m_devicechange_first_call = false;
   }
-  return GetNoReply();
+  return std::nullopt;
 }
 
-IPCCommandResult USB_HIDv4::Shutdown(const IOCtlRequest& request)
+IPCReply USB_HIDv4::Shutdown(const IOCtlRequest& request)
 {
   std::lock_guard lk{m_devicechange_hook_address_mutex};
   if (m_devicechange_hook_request != 0)
@@ -103,7 +103,7 @@ IPCCommandResult USB_HIDv4::Shutdown(const IOCtlRequest& request)
     m_ios.EnqueueIPCReply(*m_devicechange_hook_request, -1);
     m_devicechange_hook_request.reset();
   }
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 s32 USB_HIDv4::SubmitTransfer(USB::Device& device, const IOCtlRequest& request)
diff --git a/Source/Core/Core/IOS/USB/USB_HID/HIDv4.h b/Source/Core/Core/IOS/USB/USB_HID/HIDv4.h
index 3824e97621..d54d598eac 100644
--- a/Source/Core/Core/IOS/USB/USB_HID/HIDv4.h
+++ b/Source/Core/Core/IOS/USB/USB_HID/HIDv4.h
@@ -24,16 +24,16 @@ public:
   USB_HIDv4(Kernel& ios, const std::string& device_name);
   ~USB_HIDv4() override;
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
 
   void DoState(PointerWrap& p) override;
 
 private:
   std::shared_ptr<USB::Device> GetDeviceByIOSID(s32 ios_id) const;
 
-  IPCCommandResult CancelInterrupt(const IOCtlRequest& request);
-  IPCCommandResult GetDeviceChange(const IOCtlRequest& request);
-  IPCCommandResult Shutdown(const IOCtlRequest& request);
+  IPCReply CancelInterrupt(const IOCtlRequest& request);
+  std::optional<IPCReply> GetDeviceChange(const IOCtlRequest& request);
+  IPCReply Shutdown(const IOCtlRequest& request);
   s32 SubmitTransfer(USB::Device& device, const IOCtlRequest& request);
 
   void TriggerDeviceChangeReply();
diff --git a/Source/Core/Core/IOS/USB/USB_HID/HIDv5.cpp b/Source/Core/Core/IOS/USB/USB_HID/HIDv5.cpp
index dfed41fb4e..d1f5ed3783 100644
--- a/Source/Core/Core/IOS/USB/USB_HID/HIDv5.cpp
+++ b/Source/Core/Core/IOS/USB/USB_HID/HIDv5.cpp
@@ -23,14 +23,14 @@ USB_HIDv5::~USB_HIDv5()
   m_scan_thread.Stop();
 }
 
-IPCCommandResult USB_HIDv5::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> USB_HIDv5::IOCtl(const IOCtlRequest& request)
 {
   request.Log(GetDeviceName(), Common::Log::IOS_USB);
   switch (request.request)
   {
   case USB::IOCTL_USBV5_GETVERSION:
     Memory::Write_U32(USBV5_VERSION, request.buffer_out);
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   case USB::IOCTL_USBV5_GETDEVICECHANGE:
     return GetDeviceChange(request);
   case USB::IOCTL_USBV5_SHUTDOWN:
@@ -39,7 +39,7 @@ IPCCommandResult USB_HIDv5::IOCtl(const IOCtlRequest& request)
     return HandleDeviceIOCtl(request,
                              [&](USBV5Device& device) { return GetDeviceInfo(device, request); });
   case USB::IOCTL_USBV5_ATTACHFINISH:
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   case USB::IOCTL_USBV5_SUSPEND_RESUME:
     return HandleDeviceIOCtl(request,
                              [&](USBV5Device& device) { return SuspendResume(device, request); });
@@ -48,11 +48,11 @@ IPCCommandResult USB_HIDv5::IOCtl(const IOCtlRequest& request)
                              [&](USBV5Device& device) { return CancelEndpoint(device, request); });
   default:
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_USB, Common::Log::LERROR);
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   }
 }
 
-IPCCommandResult USB_HIDv5::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> USB_HIDv5::IOCtlV(const IOCtlVRequest& request)
 {
   request.DumpUnknown(GetDeviceName(), Common::Log::IOS_USB);
   switch (request.request)
@@ -63,12 +63,12 @@ IPCCommandResult USB_HIDv5::IOCtlV(const IOCtlVRequest& request)
   {
     // IOS does not check the number of vectors, but let's do that to avoid out-of-bounds reads.
     if (request.in_vectors.size() + request.io_vectors.size() != 2)
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
 
     std::lock_guard lock{m_usbv5_devices_mutex};
     USBV5Device* device = GetUSBV5Device(request.in_vectors[0].address);
     if (!device)
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
     auto host_device = GetDeviceById(device->host_id);
     if (request.request == USB::IOCTLV_USBV5_CTRLMSG)
       host_device->Attach();
@@ -78,7 +78,7 @@ IPCCommandResult USB_HIDv5::IOCtlV(const IOCtlVRequest& request)
                           [&, this]() { return SubmitTransfer(*device, *host_device, request); });
   }
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 
@@ -109,7 +109,7 @@ s32 USB_HIDv5::SubmitTransfer(USBV5Device& device, USB::Device& host_device,
   }
 }
 
-IPCCommandResult USB_HIDv5::CancelEndpoint(USBV5Device& device, const IOCtlRequest& request)
+IPCReply USB_HIDv5::CancelEndpoint(USBV5Device& device, const IOCtlRequest& request)
 {
   const u8 value = Memory::Read_U8(request.buffer_in + 8);
   u8 endpoint = 0;
@@ -130,13 +130,13 @@ IPCCommandResult USB_HIDv5::CancelEndpoint(USBV5Device& device, const IOCtlReque
   }
 
   GetDeviceById(device.host_id)->CancelTransfer(endpoint);
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult USB_HIDv5::GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request)
+IPCReply USB_HIDv5::GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request)
 {
   if (request.buffer_out == 0 || request.buffer_out_size != 0x60)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   const std::shared_ptr<USB::Device> host_device = GetDeviceById(device.host_id);
   const u8 alt_setting = Memory::Read_U8(request.buffer_in + 8);
@@ -161,7 +161,7 @@ IPCCommandResult USB_HIDv5::GetDeviceInfo(USBV5Device& device, const IOCtlReques
                                   interface.bAlternateSetting == alt_setting;
                          });
   if (it == interfaces.end())
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   it->Swap();
   Memory::CopyToEmu(request.buffer_out + 68, &*it, sizeof(*it));
 
@@ -186,7 +186,7 @@ IPCCommandResult USB_HIDv5::GetDeviceInfo(USBV5Device& device, const IOCtlReques
     }
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 bool USB_HIDv5::ShouldAddDevice(const USB::Device& device) const
diff --git a/Source/Core/Core/IOS/USB/USB_HID/HIDv5.h b/Source/Core/Core/IOS/USB/USB_HID/HIDv5.h
index 9aee63f581..0d2e102721 100644
--- a/Source/Core/Core/IOS/USB/USB_HID/HIDv5.h
+++ b/Source/Core/Core/IOS/USB/USB_HID/HIDv5.h
@@ -17,12 +17,12 @@ public:
   using USBV5ResourceManager::USBV5ResourceManager;
   ~USB_HIDv5() override;
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
 private:
-  IPCCommandResult CancelEndpoint(USBV5Device& device, const IOCtlRequest& request);
-  IPCCommandResult GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request);
+  IPCReply CancelEndpoint(USBV5Device& device, const IOCtlRequest& request);
+  IPCReply GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request);
   s32 SubmitTransfer(USBV5Device& device, USB::Device& host_device, const IOCtlVRequest& ioctlv);
 
   bool ShouldAddDevice(const USB::Device& device) const override;
diff --git a/Source/Core/Core/IOS/USB/USB_KBD.cpp b/Source/Core/Core/IOS/USB/USB_KBD.cpp
index d9ed4d68f6..9cb8ed0b4e 100644
--- a/Source/Core/Core/IOS/USB/USB_KBD.cpp
+++ b/Source/Core/Core/IOS/USB/USB_KBD.cpp
@@ -188,7 +188,7 @@ USB_KBD::USB_KBD(Kernel& ios, const std::string& device_name) : Device(ios, devi
 {
 }
 
-IPCCommandResult USB_KBD::Open(const OpenRequest& request)
+std::optional<IPCReply> USB_KBD::Open(const OpenRequest& request)
 {
   INFO_LOG_FMT(IOS, "USB_KBD: Open");
   IniFile ini;
@@ -203,13 +203,13 @@ IPCCommandResult USB_KBD::Open(const OpenRequest& request)
   return Device::Open(request);
 }
 
-IPCCommandResult USB_KBD::Write(const ReadWriteRequest& request)
+std::optional<IPCReply> USB_KBD::Write(const ReadWriteRequest& request)
 {
   // Stubbed.
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult USB_KBD::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> USB_KBD::IOCtl(const IOCtlRequest& request)
 {
   if (SConfig::GetInstance().m_WiiKeyboard && !Core::WantsDeterminism() &&
       ControlReference::GetInputGate() && !m_message_queue.empty())
@@ -217,7 +217,7 @@ IPCCommandResult USB_KBD::IOCtl(const IOCtlRequest& request)
     Memory::CopyToEmu(request.buffer_out, &m_message_queue.front(), sizeof(MessageData));
     m_message_queue.pop();
   }
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 
 bool USB_KBD::IsKeyPressed(int key) const
diff --git a/Source/Core/Core/IOS/USB/USB_KBD.h b/Source/Core/Core/IOS/USB/USB_KBD.h
index e581f3333b..460e988575 100644
--- a/Source/Core/Core/IOS/USB/USB_KBD.h
+++ b/Source/Core/Core/IOS/USB/USB_KBD.h
@@ -20,9 +20,9 @@ class USB_KBD : public Device
 public:
   USB_KBD(Kernel& ios, const std::string& device_name);
 
-  IPCCommandResult Open(const OpenRequest& request) override;
-  IPCCommandResult Write(const ReadWriteRequest& request) override;
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> Open(const OpenRequest& request) override;
+  std::optional<IPCReply> Write(const ReadWriteRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
   void Update() override;
 
 private:
diff --git a/Source/Core/Core/IOS/USB/USB_VEN/VEN.cpp b/Source/Core/Core/IOS/USB/USB_VEN/VEN.cpp
index adc535c73f..6db14fa0e2 100644
--- a/Source/Core/Core/IOS/USB/USB_VEN/VEN.cpp
+++ b/Source/Core/Core/IOS/USB/USB_VEN/VEN.cpp
@@ -23,14 +23,14 @@ USB_VEN::~USB_VEN()
   m_scan_thread.Stop();
 }
 
-IPCCommandResult USB_VEN::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> USB_VEN::IOCtl(const IOCtlRequest& request)
 {
   request.Log(GetDeviceName(), Common::Log::IOS_USB);
   switch (request.request)
   {
   case USB::IOCTL_USBV5_GETVERSION:
     Memory::Write_U32(USBV5_VERSION, request.buffer_out);
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   case USB::IOCTL_USBV5_GETDEVICECHANGE:
     return GetDeviceChange(request);
   case USB::IOCTL_USBV5_SHUTDOWN:
@@ -39,7 +39,7 @@ IPCCommandResult USB_VEN::IOCtl(const IOCtlRequest& request)
     return HandleDeviceIOCtl(request,
                              [&](USBV5Device& device) { return GetDeviceInfo(device, request); });
   case USB::IOCTL_USBV5_ATTACHFINISH:
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   case USB::IOCTL_USBV5_SETALTERNATE:
     return HandleDeviceIOCtl(
         request, [&](USBV5Device& device) { return SetAlternateSetting(device, request); });
@@ -51,11 +51,11 @@ IPCCommandResult USB_VEN::IOCtl(const IOCtlRequest& request)
                              [&](USBV5Device& device) { return CancelEndpoint(device, request); });
   default:
     request.DumpUnknown(GetDeviceName(), Common::Log::IOS_USB, Common::Log::LERROR);
-    return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_SUCCESS);
   }
 }
 
-IPCCommandResult USB_VEN::IOCtlV(const IOCtlVRequest& request)
+std::optional<IPCReply> USB_VEN::IOCtlV(const IOCtlVRequest& request)
 {
   static const std::map<u32, u32> s_num_vectors = {
       {USB::IOCTLV_USBV5_CTRLMSG, 2},
@@ -72,12 +72,12 @@ IPCCommandResult USB_VEN::IOCtlV(const IOCtlVRequest& request)
   case USB::IOCTLV_USBV5_ISOMSG:
   {
     if (request.in_vectors.size() + request.io_vectors.size() != s_num_vectors.at(request.request))
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
 
     std::lock_guard lock{m_usbv5_devices_mutex};
     USBV5Device* device = GetUSBV5Device(request.in_vectors[0].address);
     if (!device)
-      return GetDefaultReply(IPC_EINVAL);
+      return IPCReply(IPC_EINVAL);
     auto host_device = GetDeviceById(device->host_id);
     if (request.request == USB::IOCTLV_USBV5_CTRLMSG)
       host_device->Attach();
@@ -87,7 +87,7 @@ IPCCommandResult USB_VEN::IOCtlV(const IOCtlVRequest& request)
                           [&, this]() { return SubmitTransfer(*host_device, request); });
   }
   default:
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   }
 }
 
@@ -108,19 +108,19 @@ s32 USB_VEN::SubmitTransfer(USB::Device& device, const IOCtlVRequest& ioctlv)
   }
 }
 
-IPCCommandResult USB_VEN::CancelEndpoint(USBV5Device& device, const IOCtlRequest& request)
+IPCReply USB_VEN::CancelEndpoint(USBV5Device& device, const IOCtlRequest& request)
 {
   const u8 endpoint = Memory::Read_U8(request.buffer_in + 8);
   // IPC_EINVAL (-4) is returned when no transfer was cancelled.
   if (GetDeviceById(device.host_id)->CancelTransfer(endpoint) < 0)
-    return GetDefaultReply(IPC_EINVAL);
-  return GetDefaultReply(IPC_SUCCESS);
+    return IPCReply(IPC_EINVAL);
+  return IPCReply(IPC_SUCCESS);
 }
 
-IPCCommandResult USB_VEN::GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request)
+IPCReply USB_VEN::GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request)
 {
   if (request.buffer_out == 0 || request.buffer_out_size != 0xc0)
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
 
   const std::shared_ptr<USB::Device> host_device = GetDeviceById(device.host_id);
   const u8 alt_setting = Memory::Read_U8(request.buffer_in + 8);
@@ -145,7 +145,7 @@ IPCCommandResult USB_VEN::GetDeviceInfo(USBV5Device& device, const IOCtlRequest&
                                   interface.bAlternateSetting == alt_setting;
                          });
   if (it == interfaces.end())
-    return GetDefaultReply(IPC_EINVAL);
+    return IPCReply(IPC_EINVAL);
   it->Swap();
   Memory::CopyToEmu(request.buffer_out + 52, &*it, sizeof(*it));
 
@@ -157,6 +157,6 @@ IPCCommandResult USB_VEN::GetDeviceInfo(USBV5Device& device, const IOCtlRequest&
                       sizeof(endpoints[i]));
   }
 
-  return GetDefaultReply(IPC_SUCCESS);
+  return IPCReply(IPC_SUCCESS);
 }
 }  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/USB/USB_VEN/VEN.h b/Source/Core/Core/IOS/USB/USB_VEN/VEN.h
index f60359f569..3b68a6dee8 100644
--- a/Source/Core/Core/IOS/USB/USB_VEN/VEN.h
+++ b/Source/Core/Core/IOS/USB/USB_VEN/VEN.h
@@ -17,12 +17,12 @@ public:
   using USBV5ResourceManager::USBV5ResourceManager;
   ~USB_VEN() override;
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
-  IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtlV(const IOCtlVRequest& request) override;
 
 private:
-  IPCCommandResult CancelEndpoint(USBV5Device& device, const IOCtlRequest& request);
-  IPCCommandResult GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request);
+  IPCReply CancelEndpoint(USBV5Device& device, const IOCtlRequest& request);
+  IPCReply GetDeviceInfo(USBV5Device& device, const IOCtlRequest& request);
 
   s32 SubmitTransfer(USB::Device& device, const IOCtlVRequest& ioctlv);
   bool HasInterfaceNumberInIDs() const override { return false; }
diff --git a/Source/Core/Core/IOS/WFS/WFSI.cpp b/Source/Core/Core/IOS/WFS/WFSI.cpp
index d6939ec6d1..354229b29b 100644
--- a/Source/Core/Core/IOS/WFS/WFSI.cpp
+++ b/Source/Core/Core/IOS/WFS/WFSI.cpp
@@ -124,7 +124,7 @@ void WFSIDevice::FinalizePatchInstall()
   File::CopyDir(WFS::NativePath(patch_dir), WFS::NativePath(current_title_dir), true);
 }
 
-IPCCommandResult WFSIDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> WFSIDevice::IOCtl(const IOCtlRequest& request)
 {
   s32 return_error_code = IPC_SUCCESS;
 
@@ -546,7 +546,7 @@ IPCCommandResult WFSIDevice::IOCtl(const IOCtlRequest& request)
     break;
   }
 
-  return GetDefaultReply(return_error_code);
+  return IPCReply(return_error_code);
 }
 
 u32 WFSIDevice::GetTmd(u16 group_id, u32 title_id, u64 subtitle_id, u32 address, u32* size) const
diff --git a/Source/Core/Core/IOS/WFS/WFSI.h b/Source/Core/Core/IOS/WFS/WFSI.h
index 6dc784911d..91a924c05b 100644
--- a/Source/Core/Core/IOS/WFS/WFSI.h
+++ b/Source/Core/Core/IOS/WFS/WFSI.h
@@ -37,7 +37,7 @@ class WFSIDevice : public Device
 public:
   WFSIDevice(Kernel& ios, const std::string& device_name);
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
 
 private:
   u32 GetTmd(u16 group_id, u32 title_id, u64 subtitle_id, u32 address, u32* size) const;
diff --git a/Source/Core/Core/IOS/WFS/WFSSRV.cpp b/Source/Core/Core/IOS/WFS/WFSSRV.cpp
index d589967621..c85e297608 100644
--- a/Source/Core/Core/IOS/WFS/WFSSRV.cpp
+++ b/Source/Core/Core/IOS/WFS/WFSSRV.cpp
@@ -31,7 +31,7 @@ WFSSRVDevice::WFSSRVDevice(Kernel& ios, const std::string& device_name) : Device
   m_device_name = "msc01";
 }
 
-IPCCommandResult WFSSRVDevice::IOCtl(const IOCtlRequest& request)
+std::optional<IPCReply> WFSSRVDevice::IOCtl(const IOCtlRequest& request)
 {
   int return_error_code = IPC_SUCCESS;
 
@@ -90,7 +90,7 @@ IPCCommandResult WFSSRVDevice::IOCtl(const IOCtlRequest& request)
 
     // Leave hanging, but we need to acknowledge the request at shutdown time.
     m_hanging.push_back(request.address);
-    return GetNoReply();
+    return std::nullopt;
 
   case IOCTL_WFS_FLUSH:
     // Nothing to do.
@@ -359,7 +359,7 @@ IPCCommandResult WFSSRVDevice::IOCtl(const IOCtlRequest& request)
     break;
   }
 
-  return GetDefaultReply(return_error_code);
+  return IPCReply(return_error_code);
 }
 
 s32 WFSSRVDevice::Rename(std::string source, std::string dest) const
diff --git a/Source/Core/Core/IOS/WFS/WFSSRV.h b/Source/Core/Core/IOS/WFS/WFSSRV.h
index a8ed3eb446..91c9853beb 100644
--- a/Source/Core/Core/IOS/WFS/WFSSRV.h
+++ b/Source/Core/Core/IOS/WFS/WFSSRV.h
@@ -34,7 +34,7 @@ class WFSSRVDevice : public Device
 public:
   WFSSRVDevice(Kernel& ios, const std::string& device_name);
 
-  IPCCommandResult IOCtl(const IOCtlRequest& request) override;
+  std::optional<IPCReply> IOCtl(const IOCtlRequest& request) override;
 
   s32 Rename(std::string source, std::string dest) const;
   void SetHomeDir(const std::string& home_dir);