FROM https://www.reddit.com/r/Fedora/comments/zmvkdj/8bitdo_ultimate_bluetooth_controller_working_in/
I've bought this new controller from 8BitDo and wished to use on linux, to my sadness the controller didn't work out of the box, neither by cable, the 2.4G dongle or bluetooth.
So I've tried a number of solutions and this one from u/GodOfEmus over in the 8bitdo community was the one to work for me: