The right wrist always stays level regardless of the left wrist cocking motion - the right forearm is on the inclined plane - which includes the sweetspot at impact for, lets just say a very short time, as the right forearm has a 'cross-line motion' as it straightens. This is due to the right shoulder being above the inclined plane used for release.
The right forearm whilst always in the plane of the elbow bend, it can still rotate - hence it can turn and roll also.
The right hand has about 180 degrees range of movement - approx 90 degrees either side of the elbow bend plane. If the elbow bend plane is on the inclined plane, for the hand to be vertical to the inclined plane it must have 'turned' 90 degrees also. If the elbow bend plane is vertical to the inclined plane, for the hand to be vertical to the inclined plane it must be in a neutral 0 degrees to either side - hence inline with the elbow bend plane. This these two alignments degrees match precisely.
Now unless the wrist is flat - when the forearm turns and rolls - with a fixed degree of bend (an alignment im still trying to form an opinion on either way), moves the club around in a sphere in a cone-line manner. This is dependant on the right forearm angle of approach into the ball. If the fixed degree of bend is true then the rotational movement of the right arm has to conform to this conical shape turning and rolling on the inclined plane....
One step at a time...lol. This is going to be one long thread...lol
Oops,
And don't forget, right elbow position at the release point. Someone once told me, if Homer could write another version it's primary focus would be based on right elbow position at the release point...shhhhhh.....it's a secret.
You might need a whole new forum for this subject. I'm not sure if our dinky SQL database can handle it. I might have to call Larry Ellison at Oracle and upgrade just for you.
But then again, you might knock this one out in just a few posts!