15% tire drop is a good starting point; Berto and Heine have given us a good tool towards finding what works best for each of us. Kudos to the OP and others who have built on B&H's original work.

Conventional Tire Wisdom for cycling on the road as many of us understood it prior to the popularization of 15% drop: Maximum pressure for least rolling resistance is best. Very clear now that is most often not the case.