bts
You wrote-: "It's ideal geometrically and physically for the "machine" to pull the club from the top, which optimizes the clubhead speed at impact, and push (the grip, or pp#3, to bend the shaft) at impact, which optimizes the ball speed at separation".
This is the key point that needs debating. You are implying that a swinger needs to pull the club down to impact to generate clubhead speed. I agree.
However, you then argue that an
additional push force is needed to push against PP#3 to stress the shaft at impact, thereby optimizing ball speed at separation. That's where I think that you are mistaken.
Ball speed is only a product of clubhead mass and clubhead speed at impact, and
any additional pressure-force/weight pushing against the shaft at impact will not help increase ball speed. My reason for believing that fact is based on this myth-busting argument.
http://nmgolfscience.tripod.com/collisions.htm
The only factors that affect ball speed are i) clubhead mass, ii) clubhead velocity; iii) ball mass; and iv) CER.
Jeff.