Just as aside, my Avid Mk4 has push pull control tubes for elevator and ailerons including a complex aileron "mixer" that allows the flaperons to operate as flaps and ailerons at the same time, and to fold the wings back without disconnecting anything. (Although at low speeds the system can deliver a "control reversal" condition. That only happens at low speed which usually also includes low altitude which is always a fun time to experience it.)
I dont recall any friction issues.
