I'm not using MAC so I don't want to how to label a bar. And, I don't normally label the bars in BIAB. I label them in my DAW, Reaper.

rharv said;
"Any time you put a marker (an A or B change) in the song, the preceding measure will get a drum fill at the end of it (or a 'lead in')."

But in BIAB2016 for Windows I can right click on the style change marker or blank space where the style change/part marker would be and in the dialog I can remove the check mark for "Allow Drum fill before this part marker (normal)" and no drum roll/fill when I don't want one. I'm not sure if this is true for all styles but so far so good.

Does the noise in your head bother me ?