We are talking about critical AoA on a trainer as though it is a dramatic event. It generally is not. Slower airplanes have airfoils that permit flying under positive control even after the stall has begun. This is why the flaps are located inboard. If you look at tufts of yarn attached to the top of the wing and fly the plane through the stall with good coordination of rudder the tufts go reverse inboard and gradually work their way outboard. You can be well into a stall with the typical buffeting and mush, yet the airplane is controllable. So whatever the critical AoA is, there may not be a total loss of lift. It is not an all-or-nothing proposition. Even the typical swept high speed design exhibits gentle stalling. Of course there are some exceptions, but most wings exhibit gradual stalling behavior. I was present for testing of a new swept wing one time and it simply mushed through the stall which was unnerving as we did not know exactly when to call the wing "stalled" as the airplane headed for a flat-spin.