Final fantasy VI: Speed out of sync & cut off text in launcher (382900)

Compatibility Report

• Name of the game with compatibility issues: Final Fantasy VI
• Steam AppID of the game: 382900

System Information

• GPU: AMD Radeon R9 390

• Driver/LLVM version: Mesa 18.2.4/7.0.0

• Kernel version: 4.19.1

• Link to full system information report as Gist:
  Steam System Report

• Proton version: 3.16-4

I confirm:

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

Game log

Symptoms

1.) Choppy sound/animation. Game appears to be running too fast. Music and animation seem to be synchronized with each other but both are roughly 25-50% too fast.

2.) Launcher has broken text. I have set font smoothing on in wine. Other wine applications look great. ( I know what I'm doing.) Text appears cut off around inner margines. See below.

Reproduction

Run Arch linux, install proton & steam & FF6.

Start by reviewing the linked game log, Steam system report, and launcher screenshots, then reproduce Final Fantasy VI on Arch Linux with Proton using the stated setup. Done means the game's sound and animation are synchronized at normal speed and the launcher text is no longer cut off.