Though I don't see it as actually listed as compatible with MiSTer or Pocket/Dock, I have the fairly new Hunter controller, and hoping to get it working with MiSTer. It works great with the dongle for OG XBOX, and connects wirelessly on PC with the USB dongle. However, no love on MiSTer yet. I use a keyboard to get to the mapping of this new controller, but MiSTer doesn't get past trying to press 'right' on the dpad. I even tried it wired to MiSTer vis a cable but that did nothing.
The lights on the usb dongle and controller indicate they are talking to each other at least... just not to MiSTer.
Another odd thing: Windows recognizes the Retro Fighter's dongle as... an "8BitDo Receiver (Controller)" ???
IF anyone else has this controller, would you mind reporting back if yours works on MiSTer? It's a great controller IMHO, but this info may be helpful for others before buying it exclusively for MiSTer use. Maybe support will get added?