Thanks Matt, and sorry for my late reply.

Meanwhile I encountered other minor problems with the notation in BIAB (like individual spacing of single notes so that they do not glue to the barline). Anyway, BIAB is not a notation program in the first place. The reason why I wanted to use BIAB for notation is the fake lead sheet mode in which there are always 4 bars of equal length in one stave (like in the Real Book). I don't know any other program that offers this as a default setting.