Valve continue pushing ahead with improvements to their Steam Play system with the most recent beta now being out for everyone.
Steam Play 3.7-7 is now the stable version, which includes:
- Improvements to alt-tab and fullscreen behaviour in many games.
- Fix mouse behaviour in some games and mice with high sample rates.
- Update DXVK to v0.80.
If it doesn't show up for you, restart Steam. Hopefully in future the stable updates won't require this, I imagine an improved update flow will be worked on eventually although it's not much hassle to quickly restart Steam.
Additionally, there's a very minor 3.7-8 beta available which only notes that it has "Minor compatibility fixes in preparation for future Proton versions.". While minor, the wording has piqued my interest to see what they're going to be doing.
Also, if you missed it, Valve recently expanded the whitelist too.