I've heard Linux gaming is pretty good now with a native steam client and a ton of games that run natively thanks to steamOS

And if you want to know, if a game works, check protondb.com . It's for proton, so steam, and includes a steam deck section. And many games, that don't have a native linux version, come with great tips on how to make them run, if a game does not run with proton out of the box. Most just need a different proton version, which is three clicks to change in steam.

I tried this last year. VR support, even using Valve hardware with Valve's official VR support for Linux, was not there. In SteamVR menus it was stuttering and mispredicting (everything looks shaky), and in the actual applications it was unstable. It seems like the VR devices work perfectly, but the software for rendering and presenting frames is proof of concept quality. That's basically the primary purpose of this last Windows machine so I'm kind of stuck.

There's an open source OpenXR implementation, but I heard it doesn't support hotplugging, as in if any of your devices disconnect for any reason you need to restart everything.