Name of the game to be whitelisted: The Descendant
Steam AppID of the game: 351940

System Information:

Distro: Manjaro

GPU: RX 580 8GB

Driver/LLVM version: Mesa 19.0.3/8.0.0

Kernel version: 5.0.9-2-MANJARO

Proton version: 4.2-3

https://gist.github.com/Simmonz/83350260283bb22e522f7f8b3e66360f

I confirm:

[ x] that pressing the Play button in the Steam client is sufficient.

that runtime config options are necessary to run the game.
[x ] that no workarounds other than PROTON_* env variables are necessary.

Issues

[x ] I haven't experienced any issues.
[x ] There are no issues left open for this game.

Although I consider the gaming experience equal to Windows there are remaining issues: