Yeah, there's a lot about Brandt's mussings I don't care for. When I get to actually working on it I'll post a picture of my Gary Littlejohn that had to have some custom welding done to after it got mangled between a roadie and a tree. Needless to say the lower headtube was shot so I had it welded up and then faced it at the shop i worked at at the time (Good thing those facing dies are strong). I put in an A9 lower half and kept the BMX sized upper and put a GT headset top end there (The old Pro headset with the self-adjusting spring that keeps it tight all the time). It is still on the bike after 25 years and still smooth.

I dare say that, except for the B-10 (plastic A9), if you had a problem with the tapered bearing A9 it was probably because your headtube wasn't faced properly.