Keepsake (704860) - excessive logging to /tmp/dump/user_stdout.txt

Compatibility Report

• Name of the game with compatibility issues: Keepsake
• Steam AppID of the game: 704860

System Information

• GPU: Radeon 390X
• Driver/LLVM version: Mesa 18.3.4 LLVM 7.0.1
• Kernel version: 5.0.0
• Link to full system information report as https://gist.github.com/MW2K/a51ba40c47540d54c67ae8220620a9e2:
• Proton version: 3.16.8

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.

Proton log here --> http://ulujain.org/steam-704860.log (500Kb file)

Symptoms

Game generates nearly 15Mb of logging data in /tmp/dumps/user_stdout.txt in about 1 minute of game time. Yes, I know this file is cleared on reboot, but it s woefully excessive.
Before and after ls -al of the directory:
https://imgur.com/Imq9Xs0.png

Reproduction

By playing the game. Happens every time, windowed or fullscreen. The game itself runs flawlessly, music, sound, movement, saving, loading, graphics etc, are all good.

Start by reviewing the linked Proton log and reproducing Keepsake while watching /tmp/dumps/user_stdout.txt. No source file or test is named, so trace which component produces the repeated output; done means identifying and eliminating the excessive logging without breaking the reported game functionality.