I came across this post looking for a solution to my controller nightmare. I have been fiddling with bluetooth adapters and controllers to try to come up with some seamless solution to wireless controllers working on my emulators. Currently , I have a wireless xbox one controller (connected via microsofts adapter), and a nintendo switch pro controller (connected via a mayflash magic ns). These two controllers have been working well after some initial tweaking. My issues came when I decided to add MAME to my launchbox as well as a wireless fightstick from 8Bitdo (connected via a 8Bitdo adapter). You seem like you've jumped through all the hoops and dealt with similar issues my build faces. I attempted syncing both the fightstick and switch controller to just a 8bitdo adapter, which didn't work. Connecting one would kick the other off. Then I connected both to the mayflash magic ns. Both could connect, however the 4 of the fightstick buttons were no longer useable. Any input you have I would GREATLY appreciate!