Unfortunately, we now know that a two-pilot crew cannot safely handle the silent gradual pusher system of the Boeing 737 MAX.
“Pilot Who Hitched a Ride Saved Lion Air 737 Day Before Deadly Crash” (Bloomberg) says that a three-pilot crew was able to handle the design deficiencies in Boeing’s silent gradual pusher system. (The third pilot was in one of the comfy jump seats; I enjoyed a ride once in a B757 jump seat and it is remarkably luxurious.)
One of the ideas that I’ve been in love with for years is a robot copilot up in the dome light that can see everything the pilots see and, without anyone having to certify modifications to the legacy systems, help out with suggestions in the intercom. In the case of the 737 MAX, for example, the dome light copilot could notice when the runaway-trim-by-design system is operating and suggest “hit the trim interrupt switches!”
(Alternatively, of course, the Boeings could be returned to service with the requirement that they be flown by three pilots in the cockpit at all times, like a World War II bomber or Boeing 727. (In the not-so-good old days, a heavy airplane would have two pilots to manage the flight controls, a flight engineer (i.e., a third pilot) to manage the systems, and a navigator to watch the position over relative to the ground.))