I have a Mavic Air (1st gen) and the Mavic Air remote controller (S01A) which I really like.

Which models of DJI drones can I pair that with?  Can it fly the Mavic Air 2 or the Mini 2?

And can it remember pairings with multiple drones, or do I need to repair every time I switch drone?

The original Mavic Air remote can only work with the original Mavic Air.  It uses an enhanced Wifi signal instead of Ocusync like the Air 2 or the Mini 2.  

Most of the earlier DJI remotes only work with their respective drones.  The new controller that started with the Air 2 can control that plus the mini 2, plus the new Air 2S.  The Smart Controller can control a bunch of the Ocusnyc drones as well (but not yet the Mini 2).

So, bottom line is if you want to fly your Air and one of the newer drones, you'll be switching remotes as each one will not work with the other.

Hello there daveola. Good day and thank you for reaching out. As posted above I am sorry to say that the DJI Mavic Air remote controller is not compatible with any DJI Drones and vice versa. Thank you.