What is the best way to map a "Select" action for various controllers?

I have an action for menus named “Select” that you can see here:
7624027--948298--upload_2021-11-2_12-47-14.png

As you can see, it uses the customary “affirmative” buttons for each type of controller. I would like to be able to fallback to “Button South” if the player is using a non-standard controller, but I can’t see how to do that without conflicting with these controller-specific actions I already have, particularly A on the Switch Pro Controller. What is the best way to go about handling this? My apologies if sort of thing is already in the docs somewhere that I missed.

Hi, you probably want to give a try to control schemes, that way you can create Xbox control scheme, PS4 control scheme, Switch control scheme and then Gamepad control scheme. Specialized schemes will only be used if respective device is used, and for everything else a generic scheme will be used.

That sounds like what I need. Is there more comprehensive documentation than Input Bindings | Input System | 1.0.2 somewhere? Or some examples?