An option to hide the system bars or change their colour to anything that isn't black or white - meaning navigation- and status bar would be great in order to minimize stress on the pixels of this very common burn-in area. There are apps for this problem that utilize ADB but those sadly don't support Android 12 yet. One of them probably never will because development has been suspended indefinitely. :/
The apps I think are most useful were called "Super Status Bar" by Tom Bailey and "Navigation Gestures-Swipe Controls" by xda (with which I basically copied a Samsung-specific controlscheme called "Swipe Gestures > Swipe From Bottom" available in One UI, I attached a screenshot), both found on the PlayStore. If those could be (at least partially and simplified if necessary) emulated you'd have, at least in my opinion, an advantage over the competition. Not only does it protect against burn-in, it also looks a lot cleaner than the classic Android system navigation.
Also, in the same spirit, an area-specific "Scout Mode" that doesn't invert the entire screen but instead only a number of selected areas could be helpful to slow down or even reverse burn-in caused by static, game-specific UI elements (such as scores, buttons and so on).
Hope you like the idea. (: