So here's how I do that.

First, UNFOLD the song into a linear form. That lays it out measure by measure from start to finish. At this point.... go to the end and back up to the measure you think is the unnecessary measure. Highlight it and delete it. BB will move the measures to fill the gap when it regenerates.

Play it and see if that works. If not.... you can always undo it and try a different measure.

Another option that I use OFTEN is to add about 8 or more measures to the ending area. Of course this is in the UNFOLDED format. Simply pop them in somewhere before the actual end of the song. Now.... custom make the ending you want, measure by measure including the end. There will be your custom ending.... either with a hard ending or a hold to fade.... followed by several measures of silence and then the default ending will play.... easy fix to trim that off later.

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.