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RR NDB
Howdy, you make a strong point (s). "Transitory". Not for nothing is the word "transition" heavily used in aviation. At the out set, the underlying focus is generally on the loss of autoflight, and the inability (apparent) of the crew to do some simple things, with skill and speed.
"Do nothing". Wise and elderly pilots here have said this is crucial. Do not start something that muddies the water, to eventually exclude knowing how the a/c is reacting.
Then, Set "Pitch and Power". Use a table, to select appropriate settings, if low, level and troubleshoot, if high, await the return of accurate A/S.
There is a stark chasm between the loss of automatic flight, and the manual control that followed.
For instance, the autopilot started to "do nothing" the moment it quit. It did not reset Pitch and Power, though of the two flight regimes, it was better equipped to do it. The protocol at the time was to set the two after consulting a table.
Does the computer not know the correct P/P? Of course it does, its memory is nearly foolproof. Whilst the computer knows the settings, the life of the a/c depends on pilots using a loose leaf reference, which they must locate, then consult?
So, the computer has already accomplished that which the designers have said the crew must now do, to save the flight path.
I had an instructor once, a Naval aviator whom I admired greatly. I asked him once what he disliked most about flying. He said.... "surprises".
Thus transition. RR NDB you eloquently state "graceful degradation". "Degradation" is an unfortunate term, no? The bottom line here, for me, is the apparent lack of attention and design invested in the transition between one regime and the next.
Should the computer handle the "middle ground" in a/p loss due UAS?
At this critical point, the a/c is left in the middle, to include the passengers.
It is easy to say the crew were not up to the task. Until the final report, and more important traces are available, I make no conclusions. I only ask that folks here try to remain doubtful of the entire context, and not judge ahead of time.
most respect to all.