Think of your left arm as a piece of string. Use your Right Arm to stretch it out and keep it stretched at least until Follow Trough; extension without tension, a pulling of the left arm where the heel of the right hand presses against the left thumb (not a push). Use the pull on #3 for shorter shots to give you the precise idea of where the club's sweet spot is located.
Extensor Action is exclusively the steady effort to straighten the bent right arm.
Yoda quote: "The Right Elbow actuates the #3 Accumulator Roll (Rhythm). Right Tricep Extensor Action against the Checkrein Action of the Left Arm controls the Right Elbow. When you control the Right Elbow, you control the rate of Clubhead Closing."