As I said, the whip stalls issue was pedantry
At least with G-BBLA the type was cleared for spinning.
As you imply, the AAIB did not prove that the aircraft was out of w&b, this could not be done because the right hand seat had broken free of it's rail.
What they did do was to assess the probable position of the seats, based on the known length of the crews legs and their weights, concluding that the cofg was
probably 0.2" forward of the forward limit.
Whether this was significant in an aircraft that had demonstrated a nose high spinning attitude is beyond my competence to assess.
For me, the lesson from this sad accident, was that a PA28 can and will bite if given the opportunity, even when crewed by people with a total of 20,000 hours time.
Yes, I agree that the Hershey bar and taper wings give different handling characteristics, I\'ve flown PA28s with both types, including the Arrer IV and the 200B.
As far as I am aware, none of the taper wings have ever been certified for spinning, so the -140 is the closest reference point for which Piper data exists.