You can install whatever apk you want on your Oculus Quest.

My quest is currently sitting in a drawer because it refuses to play the games I already bought unless I "verify" my "meta account" - which they demanded I create in order to use the oculus locally - by uploading my drivers license. Which I, of course, refuse to do.

Last I checked you needed either a developer account or a jailbreak to load "whatever apk you want" onto the quest, and there didn't seem to be any jailbreaks around.

If this state of things has changed, please do share! I would love to be able to actually use the hardware I already paid for.

As long as you're running Zuck's spyware OS. The frame is a a linux box with fancy packaging and peripherals. You will be able to put arch on the frame and turn your new singular hobby into building drivers.

But can I uninstall Meta Horizon OS and install Gentoo?

Gotta get that -O3 flag.