I have trouble doing blazit on one of my Nintendo switch controllers and the other one is good at 1-2 could I switch controllers mid run

I mean, I don't see why not. As long as it doesn't have any turbo buttons it should be fine.

i think you could, its fair game for smo, and idk why it would be different for smb(2 totally separate games, I know, but its just one game where I know its allowed) so yeah, i don't see a reason why they wouldn't allow it (unless, like @AngryKermit said, it has turbo buttons or some other thing like the ability to do l+r) but, yeah just do it and if the run gets rejected, welp that sucks

super common thing in sm64 speedruns for the runner to switch to a hori for bowser throws