I just came across the AppCompat buckets and these seem to be somewhat similar to what the Device Profile Selector Plugin does for Android - getting more infos on the system the game is running on to adjust settings.
But I cannot find any information on this, only questions from many years ago that actually did not get answered.
Looking into Engine BaseCompat.ini , in 4.26 it looks like modern GPUs are missing. And a comparison with 5.0.1 shows, that this file has not been touched over years.
Is my assumption correct, that this actually is a ‘dead feature’?
At least, docs should get an update.