Huzzah! Proton Experimental now automatically disables the unimplemented DLL that was causing the crash previously. If you load up NASB using Proton Experimental, it now JUST WORKS.

Some important notes for incoming Linux users:

• Nvidia cards tend to suffer greater slowdown.
  • Do not try forcing PROTON_USE_WINED3D. This makes the issue worse
  • Glorious Eggroll seems to help shore up NVIDIA issues considerably
  • GE (as of the time of writing) hasn't incorporated the new Proton Experimental workaround, so you may still need to try one of the suggested tweaks
• Online requires a solid 60 FPS to enjoy without heavy rollbacks. Try lowering graphical settings to LOW, especially if:
  • Online seems to play out in slow motion
  • One or two stages feel consistently laggy, regardless of connection
  • You always seem to have zero "green bars"
    • These green bars represent how many frames ahead your machine is able to render the scene