Don't know if Orange45 runs Cruiser Brothers or not but Cruiser Brothers seems to be entertaining the idea of stocking these. If people signed up, I bet it could be a reality. Also, the 40 Channel came out with this review. Not exactly how a 40...
These guys are the US based distributor for Terrain Tamer:
https://cruiserbrothers.com/product-category/components/
Who knows, maybe with enough buyers they could end up stocking these springs.
I read your article and I'm excited for your follow up. Did you have the medium load ome springs? Also, how did they handle washboard roads? I think that is where the parabolics will really shine since they are lighter weight. Unless the dampers...