Yoda, what is the best way to achieve this feel? In 10-6-b-2 is the Right Arm
EA along the plane, or still below it?
You are always stretching the left arm in the direction it is pointing. Hence, the 'stretch' will always be Below Plane.
In addition to the 'Armless Sleeve' Drill (which can be replicated with a piece of string looped around the left shoulder), one of the best ways to get this Feel -- without a club -- is to grasp the left wrist with the fingers of the right hand (principally the thumb and forefinger) and simply take the left arm to the Top.
Then, do the same thing gripping the thumb and forefinger of the left hand with the last three fingers of the right hand.
Finally, just grip the left thumb, and make the same motion.
With a club, seek to reproduce these same Feels (of Extensor Action and the correct Right Elbow Action), and enjoy the fruit of your labor!