The intros and ending credits are almost always on the same track as actual book content. Same goes for disc change notifications—those are never on separate tracks (thus ABB can't delete them). In other words, ABB can combine tracks, but it can't split them
Ah, yes, you are right. I thought you were talking about separate tracks. Those can easily be removed, but ABB does not allow tracks to be split.
I am a UNIX command line guy and have found the possibility to directly manipulate the manifest file useful, e.g. to programmatically apply some sort of change to all track names at once. But I agree such occasions are quite rare.