I am the guest answering. The other guest is the guest who asked.Rather not argue semantics based upon your 4 shape/7 shape distinctions. As I said, that's looking at the books, not the people who sing in the churches they sing in.
I am speaking in general terms about communities of singers, you are speaking specifically in terms of which shape note (4 or 7) are connected with sacred harp and shape note.
I'm sure my knowledge is no greater than your own. I think we are, again, speaking from different perspectives. The communities are the meaningful distinctions to me, not the notes.
In terms of which is the stronger tradition, I do believe it is the African American communities traditions. They were adapted and incorporated into the black gospel traditions in ways which the Anglo American traditions weren't. Rather, the latter became more and more isolated, and didn't develop the song traditions into the bluegrass and country hymn singing traditions as did the African American tradition with gospel music.
Does that explanation make better sense of what I mean by "more developed" and "stronger tradition"?