And in the original 737 design, the only thing automatically adjusting the trim would have been an autopilot thing, making small but persistent adjustments, not a full on nose dive at over 1G, losing significant altitude that takes time to regain.
Pretty sure that's not true. There are two things that, without MCAS, are *supposed* to cause the stab trim to move: the pilots trim switches and the autopilot. But if their is a fault in either of those, or the wiring between them and the motors, or if there is a mechanical fault in the system, then the system can go haywire. (The reason it has that grasp and hold item in the checklist is in part because there are mechanical failure modes where unit can move on its own, and the pilots can stop it.) Again, the procedure outlined in the FCOM/QRH is to stop the trim from moving, and it just doesn't ask or even mention anything about the cause.
If the MCAS were disclosed, cutting out the stab trim switches would not be a secondary action in this instance of violent downward trim. You do not have time to even do that if this error happened at low enough altitude and it would be very difficult to take your eyes off the ground to flip switches on the ceiling if it happened out of the blue at low altitude and you are in an unexpected free fall.
I think basically the first part is true: if the pilots were aware of MCAS, they would have been more likely to act to shut out the trim motors. However, the ET pilots did know this (or could have) and didn't, so there is also a training requirement. The second part about time is still dubious to me. MCAS actually us unlikely to activate near the ground as it cannot operate when flaps are out. So you'd have to be near the ground due to something weird happening already for MCAS to be a factor there.
Also, the switches are on a lower console, not that it matters,
If it's the second action on a paper in flight emergency reference manual, it works better if you have time to refer to the manual before you are dead. Esp if you are a seasoned 737 pilot who has learned all the important bits of the 737, and then you are told the MAX is exactly the same.
Pretty sure the stab runaway procedure is *supposed* to be a memory item, meaning the pilots should know it. But the book exists because nobody remembers everything in an emergency. But again, this is not an ordinary book. It is designed to be used in an emergency, and has large type, thumb indexed sections, red to outline the emergency stuff. The idea is that while one person is handling the aircraft, the other can grab this and get critical information out of it. Whether this is true in practice, I don't know. But it is definitely intended that pilots can quickly access emergency procedures.