To quote a reply I received yesterday from Dahon Tech in the Dahon Forum,
"Yes, the InterLock joint will show up on more bikes in the future, although not the Ritchey steel frame bikes."
BTW, Gary Hobbs built up the Dean Ti that I later had the Dean factory put BTCs on. The BTCs are the gold standard in couplers, but the IJT looks like a strong contender, and lighter ... but it may not be available as a standalone part.