That shouldn’t really affect graphics performance though, just make sure your cpu is good enough. I’m on a 5800X using PBO undervolting however I only fly GA or gliders.
PS. it’s not 4k but better than 2k (with about the same performance), I use this custom res because dlss (quality) downscales it very nicely to 1080p. 4k is possible but only with markedly reduced graphics and for me that’s not worth it.