I set the FL Studio VST to -8 beats so the bar numbers line up with Biab, as FL Studio has no bar offset adjustment.
To get it to render without the count-in bars just highlight all bars in the chord sheet then render.
If you want the count-in bars set the FL VST to 0 and don't highlight bars in chord sheet unless you want to render selected bars.

Using Alt+F8 you can solo the BB track and generate up any sections while playing back in sync the other tracks in FL to get what you need to fit the FL song.
This way works a lot better than the current BBPlugin state.

Watch: https://www.dropbox.com/s/r0j2kcqlteg9a31/BB32-FL-Studio-VST.mp4?dl=0