Think I finally figured this out, see picture attached for what you'll need. You'll need to create the corresponding ports in loopMIDI and make sure you have them selected in MIDIberry as shown.
Then launch MIDI2LR, there should now be a file called "DisabledControllers" in AppData\Roaming\MIDI2LR, open it in notepad and set the 2 values as highlighted and save, .
Now close and reopen LR and you should be good. I've found I need to click "restart app" in MIDIberry each time I reconnect the UD-BT01, but that hasn't bothered me.