Has anyone tried looking in settings --> about device --> status --> Bluetooth ID. Writing that down. Connecting via OTG cable and then pairing with the address previously written down?
Sure it requires that you have an OTG cable to connect directly with, but it should work that way. My understanding is that there's just more hoops to jump through to get the BT ID programmatically (if it's even possible at all now) so by grabbing the address manually yourself and pairing the device over OTG you should be fine to disconnect and use the controller wirelessly with the app after.
EDIT: I tried this, it doesn't work. Manual pairing won't work since the server won't start due to the locked out Bluetooth access.