TNN Motor Sports Hardcore TR (393540) - Requires .NET 4.0 to run

Compatibility Report

• Name of the game with compatibility issues: TNN Motor Sports Hardcore TR
• Steam AppID of the game: 393540

System Information

• GPU: GTX 970
• Driver/LLVM version: nvidia 396.54
• Kernel version: Linux hellsing 4.18.0-10-generic
• Link to full system information report as Gist: https://gist.github.com/Arucard1983/22f4fcef320cf277ed54fe719f28ae81
• Proton version: 3.16.4-beta

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

Log gist: https://gist.github.com/Arucard1983/6f7db0d770e30628466861374e7b9179

Symptoms

The Game won't start at all, unless you install .NET 4.0 Framewrok, which can be done by installing winetricks and protontricks.
Once done, just type on the Terminal:
$ python3 protontricks 393540 dotnet40

Once installed .NET 4.0, the game launcher starts, and it works as expected.

Reproduction

Just click Play, and after some seconds, nothing happens.

Final Remarks

This game is actually a licensed PlayStation Game sold along a custom fork of the Libretto PCSX emulator, along a .NET program that works as a configuration tool and launcher.
The game's vendor displays the GPL code on their Support Page, so there's no GPL violations.
And also the forked emulator works without the copyrighted PS1 firmware, that Sony would never license it outside the PlayStation Store games!

The report names no repository files or tests. Start by reproducing the launch failure with Proton 3.16.4-beta, compare behavior with and without the reported dotnet40 workaround, and inspect the linked logs; done would mean the game's startup behavior is resolved or its compatibility status is clearly established.