Wing tip design?
 

theres a big diffrence between Master and APC, but they both are props, 2 blades, same diameter and pitch, even if the master didnt flex they wouldnt do the job the same way, but true, they both fly the plane.
what im talking about is improvements, we cant let the plane stop elvolving. the wright brothers had a plane that flew, that was its job, why make it better?
Sport flying these things wont matter, personaly i dont go changing props by fractions in pitch, i just bung on a 10x6 or 10x4 and go fly, i dont change plugs, only when it dies. but for the comp guys, a change of plug can make the world of diffrence, this is where this tiny effect would be noticed