I walked into the CES convention area located in the Venetian, which had quite a focus on the smaller photography vendors. Among the first things I saw was the Black Rapid booth.
There weren’t any official announcements, but I mentioned to them my Arca dilemma and my eventual solution. They were nodding from the start, and mentioned they had a solution that was just about ready to exit the development phase. Expect to see something from them before the Fall. My guess is that it will be significantly less than the setup I wound up with – I hope to get a chance to play with it!