GTA4 and San Andreas both wont work, but are known to work with Nine Standalone

[Alexmitter]

Compatibility Report

• Name of the game with compatibility issues: GTA IV, GTA San Andreas
• Steam AppID of the game: 12210, 12120

System Information

• GPU: Radeon VII, also known as Vega20
• Driver/LLVM version: Mesa 19.1.0 DRM 3.27.0, LLVM 9.0.0) Padoka unstable PPA
• Kernel version: 5.0.0
• Proton version: Proton 3.16-6 Gallium Nine Extras 0.3.0
• https://gist.github.com/Alexmitter/20070d7f631eaf9574c334b36b3061c4

GTA SA Proton Log: https://gist.github.com/Alexmitter/b77ef5eaa0d5f2df0b7c40742968ccb3
GTA IV Proton Log: https://gist.github.com/Alexmitter/1dfa2b632a8638312ba67b0dbbaffe30
My user_settings.py: https://gist.github.com/Alexmitter/0077f61b6017af6ac0df6baa0c5a7b71

Symptoms

GTA:SA: Nine is clearly in usage as after start, I get the GPU and Resolution selection, but after clicking OK, it result in the Game opening for a second, displaying a black screen and closing again.
Starting the gta_sa.exe with my Systems Wine with Nine Standalone let the game start and run perfectly.

GTAIV: Always starting with Wines D3D implementation, no reaction to any variable change. To be clear, the Steam Overlay is always working, so WineD3D is clearly in use. Can not test that with Nine Standalone as GTA IV looks for steam running on start.