Hi,
the greater rudder deflection you need during knife-edge with starboard wing up sounds much like too little or no sidethrust. (slipstream effect)
Are you sure you need up-elevator during knife-edge? Normally you need slight down-elevator (amount depending on CG) during knife-edge, a little bit more when flying k.e. with the starboard wing up. This is due to he different angle of attack of the propblades as the flight direction differs considerably from propaxis. Known as P-factor it is mostly experienced when flying hi-power and high angle of attack situations like glidertowing where the tractorplane yaws to the left.
Hope the explanation was helpful,
Andre