I tried a PS4 controller on kitty and it technically works, but still has lag/stutter on both analog sticks. Interestingly the stutter is not as bad as on the 8bit Do, but still not really usable. The dpads on both are very jumpy too.
Happy to do more diagnostics or give info if it would help. I'm on Pop OS btw, so maybe its their fault? In my understanding it's still a lot of Ubuntu underneath though.
Thanks for the fast response! In the meantime, I'll work on my keyboard skills, or maybe experiment with pasting my save in/out of web and console versions :)
(I'll also look for my 360 controllers and update if I try them)
Edit: Oh wait, I remembered that sometimes wireless is the problem. My PS4 controller works fine when plugged in via USB! But it's still weird that there's such a difference between bluetooth and wired. And the 8bitdo is wireless but not bluetooth, its little dongle should make it look the same as any USB to the OS (and it works fine on the web player). So I think it's not just a bluetooth issue either.