As I understood, the input res. of pimax 4k should be 12801440 per eye (upscaled to 19202160). I used Piplay 18.104.22.168 and a Pimax 4K with IL2 BoS and I noticed that images are slightly shifted to the outside for each eye, that results by a narrow black bar on inside of each eye view, and finally by a kind of black bar in middle of view, that beain can mosty ignore, but it is here. I do not have this probem with DCS or SteamVR home. As il2 BoS is very sensitive to steamVR input, I had a check of resolution displayed in “setting/developer” menu of steamVR.
I have the following information (I do not use SS at the moment, neither in SteamVR or on Piplay) : Res/eye = 1612*1989 !
Why do I have those numbers ? They are not on the same ratio : 1280/1440 = 1.125, 1989/1612 = 1.234, and 1612/1280 = 1.29, 1989/1440 = 1.38 !
My steamvr.vrsetting has no entry at all for pimax or other HMD.
EDIT1 : on top of that, it looks like IL2 BoS is not able to have the same resolution information than SteamVR, because it displays a resolution of 997x1492 for a resolution of 1209x1492 shown steamVR !
EDIT 2 : I found that if I modify IPD I also modify the resolution displayed in SteamVR ! With 50 as IPD I have a resolution of 1700x1989 and with 80 as IPD I had a resol of 2000x1989…