Something like this maybe?

src/Cafe/Filesystem/fscDeviceHostFS.cpp

@@ -1,6 +1,7 @@
 #include "config/ActiveSettings.h"
 #include "Cafe/Filesystem/fsc.h"
 #include "Cafe/Filesystem/fscDeviceHostFS.h"
+#include "Cafe/Filesystem/FSPath.h"
 
 #include "Common/FileStream.h"
 
@@ -157,7 +158,7 @@ bool FSCVirtualFile_Host::fscDirNext(FSCDirEntry* dirEntry)
 	return true;
 }
 
-FSCVirtualFile* FSCVirtualFile_Host::OpenFile(const fs::path& path, FSC_ACCESS_FLAG accessFlags, sint32& fscStatus)
+FSCVirtualFile* FSCVirtualFile_Host::OpenFile(const FSPath& path, FSC_ACCESS_FLAG accessFlags, sint32& fscStatus)
 {
 	if (!HAS_FLAG(accessFlags, FSC_ACCESS_FLAG::OPEN_FILE) && !HAS_FLAG(accessFlags, FSC_ACCESS_FLAG::OPEN_DIR))
 		cemu_assert_debug(false); // not allowed. At least one of both flags must be set
@@ -226,55 +227,7 @@ class fscDeviceHostFSC : public fscDeviceC {
 		// todo: implement caching.
 		*fscStatus = FSC_STATUS_OK;
 
-		// explore directories recursively and find the matching cases.
+		FSPath correctedPath = FSPath::Convert(pathString);
-		std::filesystem::path path = pathString;
-		std::filesystem::path relPath = path.relative_path();
-		std::filesystem::path correctedPath = path.root_path();
-
-		// helper function to convert a path's alphabet characters to lowercase.
-		auto static lowercase_path = [](std::filesystem::path const & path)
-		{
-			std::wstring string = path.wstring();
-			for (auto& i : string)
-			{
-				i = std::isalpha(i) ? std::tolower(i) : i;
-			}
-			return string;
-		};
-
-		bool found;
-		for (auto const &it : relPath)
-		{
-			found = false;
-			std::error_code listErr;
-			for (auto const& dirEntry : std::filesystem::directory_iterator{correctedPath, listErr})
-			{
-				std::filesystem::path entryName = dirEntry.path().filename();
-				if (lowercase_path(entryName) == lowercase_path(it))
-				{
-					correctedPath /= entryName;
-					found = true;
-					break;
-				}
-			}
-
-			// if we can't iterate directory, just copy the original case.
-			if(listErr)
-			{
-				correctedPath /= it;
-				found = true;
-			}
-
-			if (!found)
-				break;
-		}
-
-		if(!found)
-		{
-			*fscStatus = FSC_STATUS_FILE_NOT_FOUND;
-			return nullptr;
-		}
-
 		return FSCVirtualFile_Host::OpenFile(correctedPath, accessFlags, *fscStatus);
 	}
 

src/Cafe/Filesystem/fscDeviceHostFS.h

@@ -1,9 +1,10 @@
 #include "Cafe/Filesystem/fsc.h"
+#include "FSPath.h"
 
 class FSCVirtualFile_Host : public FSCVirtualFile
 {
 public:
-	static FSCVirtualFile* OpenFile(const fs::path& path, FSC_ACCESS_FLAG accessFlags, sint32& fscStatus);
+	static FSCVirtualFile* OpenFile(const FSPath& path, FSC_ACCESS_FLAG accessFlags, sint32& fscStatus);
 	~FSCVirtualFile_Host() override;
 
 	sint32 fscGetType() override;

src/Cafe/IOSU/legacy/iosu_boss.cpp

@@ -649,7 +649,7 @@ namespace iosu
 
 					// create/open fad db content
 					BossStorageFadFile fad_content{};
-					fs::path db_file = ActiveSettings::GetMlcPath("usr/boss/{:08x}/{:08x}/user/common/{:08x}/{}", (uint32)(it->title_id >> 32), (uint32)(it->title_id & 0xFFFFFFFF), it->account_id, taskIdStr);
+					FSPath db_file = ActiveSettings::GetMlcPath("usr/boss/{:08x}/{:08x}/user/common/{:08x}/{}", (uint32)(it->title_id >> 32), (uint32)(it->title_id & 0xFFFFFFFF), it->account_id, taskIdStr);
 					if (!fs::exists(db_file))
 						fs::create_directories(db_file);
 
@@ -800,7 +800,7 @@ namespace iosu
 			strncpy(fileName, (char*)&it->task_settings.settings[TaskSetting::kFileName], TaskSetting::kFileNameLen);
 
 			//  mcl01\usr\boss\00050000\1018dd00\user\<persistentId>\<storageName>\<filename>
-			fs::path path = ActiveSettings::GetMlcPath("usr/boss/{:08x}/{:08x}/user/{:08x}", (uint32)(it->title_id >> 32),
+			FSPath path = ActiveSettings::GetMlcPath("usr/boss/{:08x}/{:08x}/user/{:08x}", (uint32)(it->title_id >> 32),
 				(uint32)(it->title_id & 0xFFFFFFFF), iosuAct_getAccountIdOfCurrentAccount());
 			path /= directoryName;
 

src/Cafe/TitleList/TitleInfo.cpp

@@ -289,7 +289,7 @@ void TitleInfo::CalcUID()
 	}
 	std::error_code ec;
 	// get absolute normalized path
-	fs::path normalizedPath;
+	FSPath normalizedPath;
 	if (m_fullPath.is_relative())
 	{
 		normalizedPath = ActiveSettings::GetPath();

src/Common/unix/FileStream_unix.cpp

@@ -10,7 +10,7 @@ FileStream* FileStream::openFile(const wchar_t* path, bool allowWrite)
 	return openFile2(path, allowWrite);
 }
 
-FileStream* FileStream::openFile2(const fs::path& path, bool allowWrite)
+FileStream* FileStream::openFile2(const FSPath& path, bool allowWrite)
 {
 	//return openFile(path.generic_wstring().c_str(), allowWrite);
 	FileStream* fs = new FileStream(path, true, allowWrite);

src/Common/unix/FileStream_unix.h

@@ -1,4 +1,5 @@
 #pragma once
+#include <Cafe/Filesystem/FSPath.h>
 #include "Common/precompiled.h"
 
 class FileStream
@@ -6,7 +7,7 @@ class FileStream
  public:
 	static FileStream* openFile(std::string_view path);
 	static FileStream* openFile(const wchar_t* path, bool allowWrite = false);
-	static FileStream* openFile2(const fs::path& path, bool allowWrite = false);
+	static FileStream* openFile2(const FSPath& path, bool allowWrite = false);
 
 	static FileStream* createFile(const wchar_t* path);
 	static FileStream* createFile(std::string_view path);

src/config/ActiveSettings.cpp

@@ -209,7 +209,7 @@ bool ActiveSettings::ForceSamplerRoundToPrecision()
 	return false;
 }
 
-fs::path ActiveSettings::GetMlcPath()
+FSPath ActiveSettings::GetMlcPath()
 {
 	if(const auto launch_mlc = LaunchSettings::GetMLCPath(); launch_mlc.has_value())
 		return launch_mlc.value();
@@ -220,6 +220,12 @@ fs::path ActiveSettings::GetMlcPath()
 	return GetDefaultMLCPath();
 }
 
+FSPath ActiveSettings::GetMlcPath(std::string_view p)
+{
+	std::basic_string_view<char8_t> s((const char8_t*)p.data(), p.size());
+	return GetMlcPath() / fs::path(s);
+}
+
 fs::path ActiveSettings::GetDefaultMLCPath()
 {
 	return GetPath("mlc01");

src/config/ActiveSettings.h

@@ -12,7 +12,7 @@ public:
 	[[nodiscard]] static fs::path GetPath() { return s_path; }
 	[[nodiscard]] static fs::path GetFilename() { return s_filename; }
 	
-	[[nodiscard]] static fs::path GetMlcPath();
+	[[nodiscard]] static FSPath GetMlcPath();
 
 	[[nodiscard]] static fs::path GetPath(std::string_view p) 
 	{
@@ -20,12 +20,8 @@ public:
 		return s_path / fs::path(s);
 	}
 
-	[[nodiscard]] static fs::path GetMlcPath(std::string_view p) 
+	[[nodiscard]] static FSPath GetMlcPath(std::string_view p);
-	{ 
+
-		std::basic_string_view<char8_t> s((const char8_t*)p.data(), p.size());
-		return GetMlcPath() / fs::path(s);
-	}
-	
 	template <typename ...TArgs>
 	[[nodiscard]] static fs::path GetPath(std::string_view format, TArgs&&... args)
 	{