Thank you for your kind and detailed answer. I have nothing to add to the main part of your explanation, it is along my thinking.
That is, I think, the basic recovery mechanism, but in the early seconds the exact response depends on a changing balance between the various effects, and these in turn depend on the exact time history of applied pitch, so it is really quite difficult to answer your questions about the first twelve seconds.
Imho it is even more difficult, when we consider that the aircraft was not that stable at all. Well, it did not depart into some kind of spin, but looking at the traces we had rolling, banking and pitching movements of the aircraft, and those might have been present due to pilot action or despite pilot reaction on aircraft behaviour. Those aircraft movements and associated flight control deflections cause aditional drag and prolong any kind of recovery.
The assumption of instantaneous pitch down by 25° assumes, that enough authority is available even with thrust at TOGA, or when thrust would be in idle we would have to consider the later application of thrust, its effect on pitching moment and the spool up time, which again would influence the acceleration. We assume, a pilot in this situation can decrease the pitch in a most expedite way by 25° and maintain exactly -10° pitch over a time period of more then 30 seconds, while still stalled despite the fact, that his aircraft is in a degraded mode of operation (not to talk about the stress of the crew itself). Those 30 seconds with an unwinding altimeter would be like ages.
I don't think PJ2 will be upset if I say that in my conversations with him he confirmed that on at least one occasion he executed a recovery from 30 deg AoA using 10 deg ND pitch - it took about 15000 ft.
I buy that value, it is a fifty percent increase against the posted values in the graph. If we further consider, that the average descent rate at that time was around 15.000´/min (at 02:11:45 at 35372 feet, 22 seconds later at 02:12:07 at 29736 feet, and that those values where present without stuffing the nose down (which would increase initally the descentrate), we can assume an aditional altitude loss of at least 5.000 feet for time delays due to this unplanned stall situation any crew would be confronted with even after this discussion here.
In a practical sense we would end up somewhere between 20.000 and 10.000 feet when starting the recovery close to FL 350 and we might crash with the same procedure when stalling at FL 250.
My harsh assesment (no offence intended) would be, it might look good on a piece of paper in a warm office, but i doubt the practical use of it.
Reduce the AOA until stall warning stops, and the sooner it stops, the better it will be.
I´m not saying that those calculations are wrong in any way, but i dont think they will lead to a practical recovery technique.