A Steamlink app was added to the Meta store recently. It supposedly allows playing streamed desktop VR. I have been meaning to try it with Steam on my Linux desktop, so I can’t really vouch for it yet, it could just not work. And who knows if Proton works for any specific VR games.
Unfortunately, the way many companies are set up these days, they require employees to use multiple different web applications to do their job. And if you’re a developer, you need many different tabs for testing scenarios.