GoJ, You still don't know that, though, do you? The prelim that Ethiopian Airlines released does not include the duration of trim inputs from the pilots. Did I miss something?
We have the info for the Jakarta flight recorders. The trim input was too little at the end. I have not seen this for ET302.
Also, why do you assume that the pilots would know that under-correcting a mistrim is a fatal error? In a world where planes fly themselves, the rule is to not do anything wrong. If the plane didn't crash yet, and you made it a bit better, you might think it will still not crash.
If you make it better, and it is better at first... but it can progressively gets worse very quickly in an exponential way... that is something that you might want to know in advance.
Any Sully would have done that instinctively, immediately, in a sec, end of the problem.
Apparently, Sully is no longer allowed to fly planes. Now the capt and copilot must verbally go through a checklist and announce their intentions and ask permissions before flipping switches and pressing buttons. This is at least what they would do if they are not aware of how fast this can go south. They may have thought the worst was over.
Unless you can clone Capt Sully and include one with every plane, that might not be a very good solution.
Just to be clear, and maybe I'm undertanding things incorrectly, the AD stresses MCAS as the issue and that the solution is to cut stab trim and then MANUALLY trim the plane. Furthermore, at a given initial speed, simply pulling up on the yoke is enough to correct the plane. So if you pull on the yoke, and the plane flies how you want it to, you think the emergency is over. You don't have to correct the trim ALL THE WAY, like you are saying would be automatic, 1 second, done by Sully. (ironically, it might take several long seconds with power). You've cut stab trim; let's further say you have disabled autothrottle. The plane is level, because you are pulling on the yoke. You are still in imminent danger... because of a level of MISTRIM of which pilots apparently do not much relevant experience and training... not because of the potential for further MCAS error.