@peterdrake Is using an asset like Rewired an option for you?: https://assetstore.unity.com/packages/tools/utilities/rewired-21676#description
Description specifically mentions solving the “hot swap” problem.
Also, are you using the “old” or “new” input system? In the new system this is all supposed to be abstracted away from you and you “just” set up verbs and listen for those verbs to activate and deactivate. When I tried it was an ass-ache, but supposedly better than old input.
@drktbl This feels like overkill. My problem isn't that I'm trying to support many exotic platforms or controllers. I'm not even concerned about keeping track of which controller is which. My problem is that, within Unity, I set up one input to map to a particular button on the controller; then I plug literally the same controller into a different machine (admittedly with a different OS) and suddenly that input corresponds to a different button. At least once I restarted Unity and found that which stick on the gamepad was the X/Y axes had changed.
I continue to be astonished how often basic, used-in-thousands-of-games functionality doesn't work by default in Unity.
To answer your last question, old. I'm using the TopDown engine, which finds the new input system not "fully documented or stable":
https://topdown-engine-docs.moremountains.com/input.html#using-unitys-new-input-system
