It might help you to know that the Elbow Plane is more of a "Curved" Plane. It theory, your hands travel down, then out. In Practice, they travel a curved path to the Ball. So,,,,if you allow your hands to swing up to a TSP or Square Shoulder Plane then you'll have more curve. If you allow your hands to stop at the height of your right shoulder, AKA Ben Hogan, then the curve is shallow and more or less can approach a straight line. So, control the curve by not changing the backstroke length from club to club.

It may also help to know that the More Shallow the Plane Angle, the more Hip Slide (Axis tilt) you need to start and keep the Right Shoulder on a downward path until release. To generate a lot of downward force you might want to use this procedure. Your right shoulder will move outward at release. "Hip Slide-then-Turn" needs to be more exaggerated when using the elbow plane.

It may also help to know that in Elbow Plane Swings, Ball position is very critical with the length of clubs you chose. The Ball position of a driver is very different than the Ball Position for a Nine Iron. This is done by changing the width of your stance. Pay close attention to the distance between your right Hip and Ball because release occurs when the Elbow nears your right hip during the downstroke and the Outward force overcomes the downward force. Narrow stances for short clubs and wider stance for longer clubs.

Last but not least is that while swinging on the Elbow Plane, your right Elbow and #3 PP are ON-Plane at Release and Impact. It's vital not to run out of right arm (Straightening) because doing so moves the Right Elbow Off Plane (Above Plane). So, keep the Right Shoulder moving.

whip,

I think the right shoulder and the axis tilt basically plays the same role on EP as on TSP even though the geometry is slightly different.

You basically bring the arms back to a place where everything is well connected (whether you're a TSP-er or an EP-er). From there, the EP-er goes deeper with the right shoulder due to more increase in lateral bend of the spine. No independent arms motion until later in the down swing - much later than if you swing on the TSP and throw the right arm off the chest during transition.