What search term do I want for "run two monitors off of one HDMI port"? Is that a thing that even exists or is that Not How HDMI Works?
"HDMI splitter" seems to be a thing that displays the same thing on both monitors; I want the thing normal people mean when they say "dual monitors", where you can put different things on each screen.
@emily
something similar this *does* exist, but mainly for "digital signage" applications and with drawbacks that probably don't make sense for what you want:
https://www.dominodisplay.com/scaler-hdmi-videowall-dda210
this can split a 1080p HDMI video into four pieces and show one of them on a single 1080p screen, zoomed 2x.
Now what is stopping someone from making a similar products that crops out two 1080p feeds from a single 4K output? I'm not sure there's a real technical limit, but I also couldn't find anything closer...
@s_ol alas, that is horrendously expensive and I may as well just *replace* my monitor with an ultrawide of equal vertical resolution