joschro02 wrote:
I'm not done here. I still don't have a good answer as to why this functionality was taken away…
The answer is “no. This does not work.”
The reason why? Nobody here knows why Apple might have removed this.
Good displays are available less expensively than the Apple Studio displays and Pro Display XDR, as well. There’s a nice top-of-the-line 42” OLED with 4K (2160p) resolution for ~USD$1000, for instance.
The old iMac displays from circa 2012 are 2560 by 1600; not that far past 1080p TV. For comparison, Apple Studio display is 5120 by 2880. (If you do want a lower-resolution non-Retina display such as a 1080p TV display, also look for info on enabling AppleFontSmoothing from the command line, too.)
Buy what works for your needs and your budget. if that’s not Apple gear, so be it.