I do not feel my right forearm move. I feel my hands move, my hips move, my elbow even. The right forearm is pure magic but I can't start it without the pivot, hips and hands moving first. The right forearm is a major alignment tracing the Plane Line, I don't want to move it out of place without my lane producer- pivot hips.
And as you make mention to often,
Penick's magic move isn't an arm move first. It is a hand shift, elbow relocation, with a simultaneous weight shift or slide.
just my two cents within the family of devoted machiners