I tested the knife edge in the full size Extra 300 today (midwing)... turns out I was wrong... it does pitch foreward towards the wheels not backward in knife edge... I guess the elevator control forces are so light that I never noticed it before. It also rolls in the same direction as the top rudder... if your holding left rudder it wants to roll left and visa versa. A decathlon definately pitches back during knife edge so if you analyse the aerodynamics on it vs. the extra you may find something.

Ty