It doesn't matter u just would match sensitivity that suites for that area of the screen. Like I play on 16:9 but my sensitivity is matched for 4:3 portion of the screen. Or maybe I'm wrong it's just I think it works like that.
so i use now Hdeg 4:3 110 fov 0% monitor and when i match it in game it feels good but was reading about 25% monitor distance bla bla bla..... got confused and in apex i play 2k rez with 16:9 should i still use 4:3 conversion?