[Yoda]

Originally Posted by Yoda

Meanwhile, both the Hands and the Clubhead proceed Down Plane to the bottom of their respective arcs (directly opposite the Left Shoulder).

Are you suggesting that both arms straight occur at the 'in line' condition with the left shoulder, and not ahead of that point? How do you reconcile this with the fact that the right arm and right wrist is still bent at impact? The only way I see you could even come close to doing that is with no/limited axis tilt, and in such a setup, the 'down' would be difficult at best, you would have a lot less margin for error.

How do you reconcile the left shoulder 'center' vs. aiming point? Does not the concept of aiming point prove that the left shoulder as the center of mass is an illusion?

Per 6-A-4, the Both Arms Straight position does not occur until the end of the Follow-Through (8-11). Until then -- well past Impact and Low Point -- the 'normal' position of the Arms prevails: The Left Arm is always straight and the Right Arm is always bent.

The bottom of the arc (of both the Clubhead and the Hands) occurs directly opposite the Left Shoulder. At this point, despite the fact that the Right Arm is still bent, the Club starts 'up and in' (1-L-15). Meanwhile, the Right Arm continues to Drive (via the Hitter's Muscular Thrust) or be Driven (via the Swinger's Centrifugal Force) toward the Plane Line (1-L-10) until it, too, becomes straight.

Regarding the Aiming Point, the fact that On Plane Thrust may be directed at a specific point on the Plane Line does not negate the Left Shoulder Center:

"Regardless of how the Lever Assembly is driven, it moves in a circle" (1-L-9).