I must admit to being confused by how the plane of the left wrist cock (the Left Arm Flying Wedge) is often not the plane on which the left wrist actually cocks (the inclined plane). Perhaps I miss the obvious.
I wrote a post on this exact point several years ago. It wasn't the easiest to write, but I did a respectable job. It would be worth the search to find it!
P.S. Thanks for lifting the 'still' from the video. Nice Turned Shoulder Plane alignments: Shaft through the Right Shoulder. Left Wrist Flat, Cocked, and Turned on Plane. Right Wrist Bent, Level, and Turned on Plane. Clubface perfect. I like it!