Switch Pro controller on Mac via Steam

[retrospect]

All over the internet (especially on Reddit) people say the Switch Pro controller works fine on Mac via Steam. It doesn't though: its a mess, with a few buttons working as they should, but other buttons doing wildly unpredictable things that shouldn't really be associated with any controller buttons. Things like closing the game, or opening a full screen low-res keyboard.

Has anyone got it working properly (over Bluetooth ideally) and if so how?

Also, does Steam Input work with non-Steam games on Mac?

Thanks