I don’t know much about the actual settings, or what FSR is, but how are you saving that the user enabled it?
Also, for your solution - i definitely recommend against bCanSaveAllSections - instead add this to your DefaultEngine.ini:
[SectionsToSave] +Section=/Script/FFXFSR3Settings.FFXFSR3SettingsThis way only that section will be force saved, and you won’t need to FIndConfigFile.
FN, for isntance, only saves the GUS.ini file to disk in the shipping game.. I am not super familiar with the timing of when GUS.ini settings are read and applied, compared to the SwapChain init, but I would have thought it was generally early enough. Can you move your custom GUS processing earlier?