I have right-clicked the bar maker and unchecked the option "Allow drum fill for bar before this part marker" BUT STILL I'm getting drum fills at the part marker changes from substyle A to B, and from substyle B back to A.
This feature don't work for MIDI Drums !
I have written a post in the wishlist a long time ago with no effect up to now.
That is a real shame because it is a very handy, useful and musical feature and we can't get it !
I'm glad to see that new BIAB users have legitimate questions about so useful features. MIDI is still used by many users and we need to get new features for MIDI.