Who said anything about zeroing out? Are you saying that #3 is inline when it gets zeroed out?
Don't confuse wristcock with the condition of the flat left wrist and #3 accumulator. They are mutually exclusive. I can see how your 10-2-D grip might make that confusing for you. Throwing the clubface at the ball makes life easier for knuckle draggers because you get to ignore rolling.
Even though the left wrist can be fully uncocked that doesn't change the fact that #3 is still in line, even though it gets zeroed out temporarily.
I may be a retard on this (among other things) but isn't the #3 Accumulator Angle set when the Left Wrist is in it's Level condition (all alignments stem from Impact).
The #3 Accumulator Angle is rolled through the impact interval but when (and if ) the Primary Lever goes to Full-Lever Extension then the #3 angle would be lost would it not?