If the reports of the Ethiopian pilot’s difficulties after following the procedure are correct, either being unable to trim manually or the perception of ineffectiveness - high force slow trim rate, this would increase pressure on Boeing and the FAA.
Furthermore, if the FAA knew of this inability (NTSB rep), then how could they issues a special approval for repositioning flights with empty 737 Max.
Might the operators / unions have a view on this.
Control force discussion and EASA views (#25) in
Boeing advice on "aerodynamically relieving airloads" using manual stabilizer trim