User blog comment:Luxionmk2/Counting BCs.../@comment-24462444-20140702184154/@comment-5007614-20140702201315

The effort involved in getting BB to 10 and having it cut in half when evolving to 6-stars isn't worth it. Easier to go from 1-5 in my opinion.

Still, lots of my units have BB level 4 or 6 as a consequence of how I level them up anyways :)