Below Plane Stretch of Extensor Action

[FL-John]

Homer mentioned in the book that the strech of Extensor Action is below plane, except for zero #3 Accumulator. My question is twofold:

(1) With zero #3 Accumulator, is the stretch going backwards along the face of the inclined plane?

(2) If there is #3 Accumulator, AND with the left arm at address, being off (and usually above) plane, how much is BELOWplane. I mean, is ithe feel of streching slightly below the plane anlge??

The reason I ask #2 is at times, as I try and utilize the below plane strech of extensor action, I think I inadvertently roll/swivel my entire left arm in an 'over the top' of my right forearm type of move.....it gets the shaft too flat going back!

Thx

FL-John