[golfbulldog]

One fault people have (me for one) . . . is NOT RELEASING #4 down the chest rather "OUT" which basically moves the hands out away from the plane rather than keeping them "in on-plane." Thus a compensatory move must be made because the radius (left shoulder to clubhead to ball) has been disrupted a miriad of compensations have to be made to get the sweetspot on the ball (standing up, flip, alligator arms . . etc. etc.).

I like your point about releasing acc.4 down...I think the whole "blast the left arm off your chest" can be a bit misleading.

I think that you blast it from above the nipple line to below the nipple line...

In this video I tried to show the stage where the pivot carries the power package to...then the acc 4 releases...and the right shoulder appears to stop rotating toward the target and goes down whilst the acc 4 releases...the left shoulder moves up quite alot as the axis tilt becomes more evident.

But the left arm moves almost independently after "blast down" of the left arm.