Just tested upping the SS slider to 2800x2800, and ill never do that again. Its a massive performance hog. Without any visual difference. I noticed sligtly less shimmering in the distance. But thats it. Definitely not worth the 10-20fps performance drop.
Nothing really changed in terms of visual clarity, i could still read the NOSE UP on the trim button of the F-16 stick with no issue, it didnt even seem like it changed.
Just put it to 2160x2160 and you're all good.