So you don't agree that the sequence of the left wrist positioning I mentioned is a good way to operate the downswing?
I do. Because that will load your right wrist and supinate your right arm and externally rotate your shoulder and flatten the club in transition so you don't come in too steep and then stall and stand up and then straighten the right arm and wrist too soon causing one to roll the forearms to square the face with an excessive closure rate or worse yet, flip before impact.
All caused by thinking the shaft plane at address has some kind of relevance, it's precisely that picture or thought of that plane line that causes people to come in too steep with an overhand throw instead of a underhand /sidearm throw. The real plane is the ground and the clubhead rests on that plane but the shaft does not.
The trick is knowing this and how to deal with the shaft as the clubhead is impaled by it. Take the shaft out, put the clubhead in your right hand and from your golfing stance make a right arm b.s. and see how your arm will load and what your wrist will do and your shoulder, your arm will supinate and your wrist will bend back and your shoulder will externally rotate, now what will that do to your left arm and hand and shoulder and the clubshaft.
The left wrist will be cupped going back till the right arm and wrist and shoulder do their thing as described above and the left wrist will flatten or even bow the clubshaft will then flatten for a more shallow entry. Then all the Goats and worms will be safe.