https://www.satcom.guru/2019/03/what...this-week.html
...The last issue with MCAS is the most significant. The flight condition that MCAS is designed for (accelerated stall) involves the column being pulled back when MCAS needs to trim nose down. This creates a conflict with the aft-column cutout. The aft-column cutout stops a nose-down "mistrim" command.
The aft-column cutout involves a signal from the column cutout switch to the FCC. The FCC software uses the input to turn off its trim commands.
The FCC removed the aft column cutout feature from MCAS commands. MCAS can trim nose down in spite of the aft column cutout being asserted. This is a grave error and must be resolved.
Human factors cannot be denied. In the event of a nose-down stabilizer uncommanded motion, the pilot will pull back on the column. That much is certain. As the airplane pitches over, the pilot will pull back harder. With the aft column cutout, the trim command will cease, the situation will stabilize, the pilot can compose themselves, trim the stab back up, and maybe hit the trim cutout switch.
Without the aft column cutout, some human beings may freeze up. They may not get to the step of trying to trim the stab back up, but instead fixate on pulling the column back. I fear this is exactly what happened in JT610.
The column cutout switches have served aviation well. Boeing NEVER should have removed aft-column cutout for MCAS. Aft-column cutout must be restored. If that means MCAS cannot work as planned, THEN SO BE IT, take MCAS out...