That's the wrong approach. When I want a centered 27" rectangle, I use software to put a 27" rectangle in the spot where I want it. I never fullscreen anything, and put secondary things around the edges, the way one would use extra monitors. There are some minor software issues to work through, it definitely requires some customization in the window manager department, but it's worth it imo.
8k/65in has the same pixel density as a 4k/32.5in, which is mid-range as computer monitors go. 16k would be nice if that was possible to buy, but this pixel density is good enough for my purposes.
You talking to someone who upgraded from a 4k/32" equivalent ("5k" 40" ultrawide) to the XDR just for the pixel density increase, and it's no contest at all: even the most casual PC user would immediately appreciate the bump.
