BTW, it looks like the joystick interface is being extended to support a broader set of devices in the incoming snapd 2.33. See:
- Joystick support for Cave Story snap (aka accessing joysticks via /dev/input/event*) - #9 by jdstrand
- PR #5203: interfaces/joystick: also support modern evdev joysticks and gamepads
Maybe some of your controllers do not work now, but will do once the above patches land.
I’m sure @jdstrand would be happy to see somebody testing his PR… 