Hey Dreadbelly,
I've been following your posts and just wanted to chime in some ideas;
How about doing a suspender/LBH belt attachment like shown here ( Low profile LB). It uses a velcro wrap that goes around the belt. This would keep your pocho-scarf from flying away in the wind. You could do this out of nylon web, leather or the poncho material itself. LBH normally have a Y shaped atachment at the back too, but with your pack pocket idea, I don't think that would be needed.
I think you've created a monster!
SERT out...