I think one's track record in making judgments on boundary cases is established only after having successfully dealt with boundary cases -- and enough to establish a level of confidence. Of things already in Unicode, what have been boundary cases between unificiation and de-unification?
The unified Latin-but-not-Cyrillic w & q (if I've recalled the two letters correctly) and Coptic/Greek characters are the only prior boundary cases I can think of. Peter
