Talked with Quarq. They don't think there would be a problem mounting the 6700 chainrings on one of the other crank setups. I would have to ship in my chainrings to be certain -- and for calibration.

So, if I want to find out, I will need to buy another crankset first to keep from being off the bike for an extended period. The price of the additional crankset doesn't take the Quarq ALL the way to SRM pricing, but it's getting closer!