I made the same decision to move from OSMDroid to B4XMap. It is now working in my PC dispatcher app and I plan to integrate it into Android client app now. Just in case: there was a bug in B4XMap - when underlying pane is resized, all feature show settings (ShowMenu, ShowCenter, etc) except ShowGrid will be set to true ignoring initialization settings. I did a fix for this basing on latest public UDG's version at that moment, and some other small fixes. Please see attached this modified version.
Sorry for such late answer, I came upon this thread only now.