I think you'll find that the cable assemblies without top-octave augmentation sound best on things like ribbon and dome tweeters, and from what you and Martinelli are saying, this may also be the case for the BMS tweeters. The π cable assemblies will sound best for Eminence, Altec and JBL compression drivers on CD horns. And something in between sounds best on Altec sectional horns - Something like a π cable assembly with C1 reduced or removed.

I think this may be what you'll find with the BMS drivers too. It will probably be something in between the flat response provided by a straight padded cable and the rising response provided by the π cable assembly. There are any number of suitable networks that will provide response in between these two, so that's where tools like Spice become useful.