What I found enlightening and interesting was that he said that the xsx would take approx 5ms to do ML upscaling, not sure what resolution that's from though.
Be interesting to know how many extra ms it takes to render 2160p from say 1440-1660p, as I don't remember there being any comparisons apart from to rtx and 4pro.
The 5ms was at 4k based on the XSX having half the ML capability of an RTX 2060 with takes 2.5ms at that resolution.
Assuming those timings are for DLSS quality mode then I think it would be using a base resolution of 1440p.