Disable gamepad device while using Steam remapping functionality

Question

I have 2 Xbox One S Gamepads that I'm trying to get to work with a game via Bluetooth on my Manjaro system (kernel 4.19.8). I'm now using xpadneo (which automatically disable ertm at boot time and provides extra functionality) but I had similar problems with xpad.

The game I'm trying to get to work doesn't feature a way to select which controllers to use and assume all controllers it can detect are valid players.

Whenever I connect a controller I see a /dev/input/js0 device being created. If I start the game at this point, the device is detected but no keys work. I tried following instructions on xpadneo to create SDL bindings but it didn't work in this case.

If I launch Steam, Steam will remap my controller to a xbox360. A new device /dev/input/js1 will appear. If I start the game at this point, two devices are detected and the keys work only in the controller remapped by Steam. Same thing happens with 2 devices, I get 2 more virtual devices and the game sees 4 controllers.

How can I disable the first device after remapping it with Steam?

Alternatively, how can I remap my keys on my controller without creating another device, so that it will behave correctly without Steam? [I doubt this one is easy or it would be part of one of the drivers]

Thanks