Removing macOS mouse acceleration is mandatory for me to not go crazy. I'm using this script now: https://github.com/docwhat/killmouseaccel

Downside is it's a one-shot sensitivity which can't be adjusted, owing to the hacky nature of it, which was semi-found-by-chance to boot. After lots of searching on threads, seems this is one of the only hacks that works, so doesn't seem to be much support from macOS on this stuff.

Used to have an app format of this so I didn't have to run the console command every time at login, but need to find an updated solution for Catalina.