You can always do this. Ignore the canned ending. Maybe even turn off the automatic endings in the settings.

Just do what I will often do. You of course know where you want the song to end. So Just go there and add 4 to 8 measures to the song at that point.
Then simply use the triple dot after the chord.... such as D... to tell BB what to do and where. That triple dot thing is a hold on the chord to a fadeout. You can get the exact ending you want regardless of anything else going on.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.