Actually, it is quite simple to create A & B parts for the User Tracks. In your song template enter a chord sequence with the A part marker and then a sequence (preferably the same) with the B part marker. When you are recording your User Track play the two parts one after another with the rhythmic variations you want for your A & B parts.

This is it - save your BIAB song and your audio file as a User Track and when you select it for another song, the A & B parts should work. I did a test of this last night for both an instrument and a drums user tracks and it worked well - I had the rhythm change with the part markers.

Now, I want to figure out whether it is possible to create fills, shots, holds and endings smile

Regards,
Oleg.