Thomas Crider has announced the release of Proton-6.21-GE-1. This is a custom build of Proton with the most recent releases of vanilla WINE. It has FFmpeg enabled for FAudio by default, and all of Proton's patches ported over to be applied to WINE, as well as Wine-staging and VKD3D.

Proton-6.21-GE-1

-Proton BattlEye patches added
-Proton CEG patches added
-Proton Forza Horizon 5 patches added
-Proton Guardians of the Galaxy patches added
-Proton Fallout76 patches added
-Proton Baldur's Gate 3 patches added
-Proton Age of Empires IV driver nag fix patch added
-Proton fsync patches updated to futex_waitv version
-Fix for error when using file browser to pick a file location added (this occurred usually in applications when you tried to specify an existing file location)
-Fix for broken mouse input in Borderlands and R6S added (was not present in 6.20, issue appeared in 6.21)
-Fix for the beamng mouse issue updated so that it does not affect non-steam games
-Bcrypt patches updated (steep works again, thanks openglfreak!)
-vulkan childwindow patches updated
-vkd3d Forza Horizon 5 patches added
-vkd3d Guardians of the Galaxy patches added
-vkd3d updated to latest git
-dxvk updated to latest git
-protonfixes uplay overlay disable function has been fixed to apply correctly when used.
-wine mono version updated
-protonfix added for ship graveyard simulator (and prologue, Thanks Alistair Leslie-Hughes!)

Notes:
-Fsync has been disabled on all Uplay titles -- it causes Uplay to hang on "Looking for patches" when initiationg a new prefix. Esync works fine.
-Various Uplay titles that have a vulkan native mode (Rainbow 6 siege) need the overlay disabled in order not to crash. DX11 mode works fine.
-For games that have a protonfix that uses the uplay overlay disable -- if creating a new prefix you will need to relaunch the game a second time. Uplay completely removes any pre-existing configurations on first launch, so any appending to the file gets removed. Upon re-launch the option will be re-appended and uplay will then see it.
-uplay likes to hang out after the game has closed -- make sure you close it in the task manager.

BattlEye games tested and working:

Ark: Survival Evolved

BattlEye games tested and not working:

Mount & Blade: Bannerlord -- hitting this issue: ValveSoftware#3706 (comment)

CEG games tested and working:

Bioshock Infinite
Just Cause 2
Black Ops II Campaign
Sid Meier's Civilization V
Mafia II (Classic)

CEG games tested and not working:

Black Ops II Zombies Mode -- exemption occurs a few seconds after getting to main menu
Black Ops II Multiplayer -- same issue as zombies mode
Warhammer: Space Marine -- bugsplats
Lara Croft and the Guardian of Light -- just hangs in the background infinitely until force killed

Download Proton 6.21-GE-1 from GitHub
Installation Instructions