Ref 1: 6-B-3-0-1 "So-except in Sections 1 and 3 (Chapter eight) the entire Left Arm, the Clubshaft and the back of the Left Hand are ALWAYS positioned against the same flat plane-the plane of the Left Wristcock motion."
Ref 2: Gallery audio for John Reiger, day at the office-iron-"the left wrist works like a hammer" but, as I understand it, not in-line with the left arm plane.
Is there a thread discussing this?
Yes. I wrote at least one definitive post on this subject, maybe two. Can't recall the title or where it is and am time constrained at the moment and can't search. Think it was in a thread where Mathew was opining on the issue.