Scott gets a wild hair
There are probably any number of objections to this idea, not least, it would be very expen$ive. What about this?
Procure an old 332. Fit it with robo-remote-controls (pilotless). Fit it with advanced recording/telemetry equipment. Fly the thing out over an ocean, and stall the thing.
That airliners are not tested for actual stall characteristics is emerging as unacceptable, IMHO.
Discuss. (Runs, hides.)