Ah, but I'm running Linux. :) (oh - and I'm the OP)
They also support Mac, and yes, Windows for those unable to escape the pull of Redmond.
Well crap. The first hit on google with "Oculus Quest version 2 mac" is recent and completely wrong apparently. Sorry.
I had a question about your Linux setup: Does Immersed VR support multiple monitors in Linux now? Or do you have to mirror a "real" 4k monitor to have it show up in your app? Edit: Ah, I've found some `xrandr` tricks that should work.