Valve has released another big update to Proton: Proton 9.0-1.

Proton 9.0-1 Latest

Previously playable only with Proton Experimental:
Dinogen Online
Photography Simulator Demo
George McGeehan Gamer Hero
The Finals
True Reporter. Mystery of Mistwood
Road to Vostok Demo
WITCH ON THE HOLY NIGHT
Lord of the Rings: Gollum
Sonic Colors: Ultimate
Command & Conquer: Red Alert 2 and Yuri’s Revenge
Command & Conquer Tiberian Sun and Firestorm
Aisling and the Tavern of Elves
Snares of Ruin 2
Insanity's Blade
Bloody Walls
Limited number of cores seen by the following games making them playable on a high core count CPUs:
Far Cry 2
Far Cry 4
The Witcher 2: Assassins of Kings Enhanced Edition
Lara Croft and the Guardian of Light
Warhammer 40,000: Space Marine
Warhammer 40,000: Dawn of War II
Warhammer 40,000: Dawn of War II - Chaos Rising
Warhammer 40,000: Dawn of War II - Retribution
Outcast - Second Contact
Prototype
Enabled nvapi by default for most games.
Started ignoring system mouse acceleration in games using raw input API.
Fixed Brawhalla showing a security certificate warning.
Fixed audio in BOOMEROAD, DORONKO WANKO, NOTTOLOT.
Fixed Civilization V Touch Only option in the launcher not working.
Improved cutscene synchronization in Immortals Fenyx Rising.
Fixed TouHou Makuka Sai ~ Fantastic Danmaku Festival Part I and II crashing during boss fights.
Fixed crash in Disaster Report 4: Summer Memories epilogue.
Improved video playback in BIOMUTANT.
Fixed Imperiums: Greek Wars launcher.
Fixed memory leaks that caused Final Fantasy XIV Online launcher crash over long time.
Fixed crash in Microsoft Flight Simulator when live weather is enabled.
Improved support for input devices with 8+ axes.
Fixed Savant - Ascent REMIX hitching during certain animations.
Fixed Super Robot Wars 30 crashing with languages other than English.
Fixed Doom Eternal audio crackling on certain setups.
Fixed Lethal Company, Phasmophobia and other Unity games crashing when a controller with a hat switch is plugged in.
Improved video playback for the following titles: Lords of the Fallen, Harvestella, Wayfinder, Sea of Thieves, and KING OF FIGHTERS XV.
Fixed default scaling for The Last Game on Steam Deck.
Fixed audio issues when playing intro video in Airborne Kingdom.
Fixed Bayonetta crashing on certain systems.
Fixed Escape from Monkey Island getting minimized on a mouse click.
Fixed audio controls and spatialization in VRChat with AVPro.
Fixed new prefix failing to initialize on filesystem that do not support copy_file_range syscall.
Updated file distribution method to save disk space.
Rebased on top of upstream Wine 9.0.
Updated vkd3d-proton to v2.11.1-49-g32ff676b.
Updated dxvk to v2.3-47-ge2a46a34.
Updated dxvk-nvapi to v0.6.4-48-g0951afb.
Added support for Steamworks SDK 1.59.