I’m no patent lawyer, but every graphic in that patent describes a 540p image being upscaled to a 1080p image. No mentions of a 2160p image, although I didn’t read the full text.
I suspect this feature is more intended to allow games like The Witcher 3 or Wolfenstein that output a really low resolution to present a better image.
Although, having tinkered with FSR3, I’m generally not impressed with AI upscaling at low source resolutions. I’ve heard DLSS does better in those conditions, but even at 1080p->4k there’s noticeable artifacts and temporal instability. I much prefer it at 1440p->4k. So I’m somewhat unsure how much I’d even want 1080p->4k, although I’d certainly try it and see, and I kinda think I don’t want 540p->1080p.
When you start getting up to/past 1080p, better texture quality >> higher resolution. I’d rather they spend the extra GPU cycles to take their 540p content from “Low” to “Medium” quality before upscaling than take it from upscaling 1080p to 2160p.