Valve Index. I currently dual-boot Windows for VR. This is the rabbit hole I went down (to be clear: SteamVR, specifically the compositor, is completely broken).
1. Install Monado with libsurvive.
2. Discover that libsurvive doesn't have the "smarts" that SteamVR has, and that calibration can be wonky (and was wonky for me).
3. Learn that you can import SteamVR calibration data. I can't do this in Linux because, well, SteamVR doesn't work.
4. Dual boot Windows with the intention to copy over calibration data.
Well, I got Monado and libsurvive running some time ago (Valve Index, X11, Nvidia), even for Beat Saber. It sadly was unplayable, because reflections were wrong in VR apps, it felt like both eyes using the same reflection angle instead of adjusting it to each eye. For close objects this was bearable, anything further away would look "wrong" and cause VR sickness. Also the FoV was wrong, it felt like a vignette around the screen edges, a good bit narrower than in SteamVR. Oh yeah, and the latest version did not build for me, used a previous one.
Performance, especially in Beat Saber, was great and better than SteamVR!
I would expect SteamVR to at least work enough for calibration. You could try switching to beta or other versions.
My guess is they focus on Proton for Steam Deck, which can not run VR comfortably (but, it can run it via USB-C docks/dongles, the power of a full Linux PC!). So we get constantly better Proton compatibility, including work on anti cheats, but VR is low to no priority. The market is pretty small, especially if you mostly worry about Index and related PC-tethered headsets. Also developing VR for Linux can't be an easy task.
I am especially annoyed that they more or less dropped the ball when it comes to Beat Saber via Proton. Beat Saber was an official launch title for Proton, but was unplayable for months [1].
Overall, if you are willing to deal with some annoyances, give it a try, it might cover your use cases.
SteamVR is playable, but not at Windows level and rough around the edges. I personally run an Index on a 4080 Super (previously 3080) via the SteamVR runtime. System details in case it matters: Arch Linux Zen kernel, X11 (i3), Nvidia drivers, SteamVR Beta, usually a recent Proton GE version. I remember playing Beat Saber, including modded [1], Until You Fall, Pistol Whip, Raw Data and After the Fall without issues. Non-steam applications outside Steam can also work, I have a launch script that sets up the env vars for Proton, should be easier via Lutris.
I see some problems however. VR itself is not as smooth as it should be, 100% playable, but not as smooth as I remember it ages ago on Windows or using a FOSS VR [4] stack (which has other issues). I don't really use SteamVR home, it sometimes takes a while to load. SteamVR window on the monitor has weird flickering issues, usually I can't get into its settings, likely i3 related. Firmware updates are mostly broken. No (I think) standby for the Lighthouses, I toggle them via Home Assistant and smart plugs.
Shout out to steamtinkerlaunch [2] for making certain settings easier to apply and ProtonDB [3] for tweaks if needed.
That's a huge show stopper for me at the moment and holding me back from switching over to Linux.