I agree with your analysis on the props, Jimcork. While I'm neither a scientist or engineer, I have done some testing of 3 blade props, and have found that they will not even come close to the efficiency of two blades. If you have a plane that is overpowered, such as my TF AC-47 with .40 engines, then running 3 blades will work fine. The reduced efficiency of the props makes it fly very scale. The down side, of course, is keeping a close eye on your take offs. You can't just horse it off the ground with engine power. The RCV engines however may work with the multi-blade stuff, since they are running lower rpm. In any event, they are some fine looking props you're getting made, Grinder.
Randy