I have tried running this using a fresh Proton CachyOS and fresh Proton-GE prefix, I've tried installing dotnet48 and dotnet46 which failed, I've created a separate
LaunchSEFLinux.bat
LaunchSEFLinux.bat
with the contents
cd .\System\..\..\ContentExpansion\System\Swat4X.exe
cd .\System\..\..\ContentExpansion\System\Swat4X.exe
and tried to launch it as an alternative .exe (there is a file in the folder already created by "eezstreet"), and I set the prefix to windows 10 mode which did about as much as I expected it to. Even tried installing the wine dependencies which werent on my system yet