Re: settings app crashes when I try and enter game mode settings
At the moment, even if you were inclined to attempt a repair install, it would not be able to complete. The bug that's blocking the "Keep files and apps" choice for a repair install has been fixed, and is available for manual download, but has not been pushed out via Windows Update yet. I believe it's supposed to go out in very early December. Information on the preview update that fixes the repair update bug can be found here: KB4586853 CU Windows 10 v2004 build 19041.661 and v20H2 19042.661
I'll add information to the topic I created when this bug was first being reported once I know that the fix is going out by Windows Update. By the time it is pushed out it may be part of an entirely different KB number cumulative update.
Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041