Not Ted, but this may shed a little more light on the subject. You need to reverse your above statement to read like this: "When using 10-5-A you Trace the True Geometric Plane Line and when using 10-5-E you Trace the Angle of Approach."
Here's some more info, hopefully it won't be confusing. These are, thanks to Ted, the words of Homer,
"The original plane is gone - don't even think about it. It's totally replaced."
Remember that, when using Angle of Approach. You can't trace something that's gone. The Clubhead COVERS the 10-5-E Plane Line and is also TRACED by the Right Forearm and #3 PP. Per 5-0, "... the Delivery Lines, in addition, must be 'Traced' by the Right Forearm."
Remember, when using Angle of Approach Procedure, you're NOT using 10-5-E as a new Plane, you're just using its baseline as a guideline for the Clubhead.
The visually equivalent Delivery Line, the Angle of Approach, always exists then using 10-5-A but unless you choose to, you're not necessarily covering it with the Clubhead.
Also, per 5-0, " The Plane Line - being the basic- can substitute for any of its "Visual Equivalents' at any time."
Angle of Approach and Arc of Approach are "Visual Equivalents" to the True Geometric Plane Line. Pick one of three and that's the one you Trace.
A quote from Yoda:
"Again, the Right Forearm always traces the selected Delivery Line. Then, depending on the procedure being used, the Sweetspot covers either the Arc of Approach or the Angle of Approach."
Hopefully that helps. It helps me to be sure to think about the three Delivery Lines seperately. Each one is used indepedently of the others to deliver the Clubhead.