I often see improper riding techniques--riders who crouch forward or press on their toes to accelerate, when this is not how EUCs are designed to operate. Pedal dipping more likely comes from a rider mishandling their EUC.
I have a King Song 18XL and have never experienced pedal dipping even once at any speed. On any EUC, I am able to reach top speed without crouching, without pressing on my toes, and without pushing my wheel out from under me. Acceleration comes from a shift in center of g