There is a lot here to read, but the discussion about MCAS sems to be about a sensor disagree.
My understanding for the need for MCAS was due to the much larger engines (without a redesigned wing) that leads to instabilities on DEP angles of attack when at certain altitudes trim adjustments are required. A software patch, MCAS, was developed to compensate for this issue, not a sensor disagree?
Was this not the reason MCAS was needed to cert the ac?