I'm familiar with the subpixel arrangement issues. My display is RGB, according to its specs and to some review I've seen before buying it (I made a point of avoiding "non-standard" panels). I only notice this with very thin fonts, since sometimes the vertical lines end up "in between" pixels.

I agree that at some point grayscale AA is good enough. But I've found that that point is at a higher DPI than I get on a 4k 32" screen. On my 24" 4k screen grayscale is good enough, so the limit is somewhere in between for me.