I’m modifying by position here a bit. In another thread (and I see now in this one too), several PC and Xbox users have stated that although MS says “4K Ultra” for Xbox promotional purposes, that it’s more like (or maybe actually is) 2k upscaled to 4k. And visually things look like something between high and ultra.
Anyway, regardless, I made my premise based on the “4k Ultra” from MS assuming that to be 100% true. Since it seem that it’s not then it would appear that right now, PC is the only way to get true 4k ultra 60 fps or whatever. Who knows? Maybe they’ll let the program use whatever RAM is available at some point to make the PC experience even better.