Running the game without changing any of the launch options worked perfectly out of the box, even with maxed-out visual settings, until I tried to use a tool, at which point the game stopped responding to input from my controller. Trying to use the tool again with the keyboard instead caused the game to freeze, and it did not recover. I had to restart Steam entirely.

I reopened the game with Proton 8.0-2 forced in the compatibility settings, and the problem hasn't happened any more. Forcing Proton Experimental works as well.