You can eliminate stuttering by using dxvk-async (search on github), however instead of stuttering parts of the geometry will sometimes flicker black. As you play the game, this stops happening, as the shader cache builds. The other reports for this game are outdated, as proton now supports the CEG drm.

IMPORTANT: If you're using plutonium, you NEED to delete steam_api.dll from your install or else it won't launch. Additionally, you NEED to disable NVAPI if you have an nvidia card, or else the game will not work.