While rebuilding my entire Android Eonon GA6166 system due to a faulty Witson SoM Board I installed the latest version of the BMW IBUS app (2.0.3).
https://www.ibus-app.de/index_en.html
Lots of new features (app opening sequence, speed sensitive volume, etc.) and this app really makes leaving the OBC functions behind while doing a head unit upgrade, a non-event.
Mike