I know this will probably have a very limmited audience, as I mostly play older games.
But ... I've found few older games, that would not display correclty at 1280x800 full screen (really bad distortion), and need to be pushed to the Go max Res.
I get that the Go can run older games at higher resolutions, but at 800, looks great, and uses less battery, which seems as a win for me.
Yestreday I installed "Lossless Scaling" and the app will fix that issue.
To sumarize, you set the game to whatever res you want (window mode), go back to lossless scaling, and use scaling mode in Auto, and Aspect Ratio, Scaling (makes no difference as the RES will be 800 on the game) ... click scale and go back to the game before the contdown expires, and it will be fixed.
I also tested scaling and setting the game to even lower res, and worked just fine, obviously lower res, more obvious there is some processing happening, tested LS1 and AMD FSR