fdr, thank you for the extensive background.
Re 'angle grinder' fixes. One of the first western public conferences where TsAGI presented a paper on high alpha aerodynamics. - In answer to a question on their approach to strakes re nose slice, why some aircraft could perform 'cobra' manoeuvres (SU27) vs those requiring extensive theoretical development (F18); 'if a particular aircraft had a problem then change the nose cone until one was found which did not roll off'. A lesson in practicality.
EASA neatly concludes the certification need for MCAS:-
"MCAS has been established to play only a limited role in augmenting the stability and stall characteristics of the aircraft in certain conditions. … needed to ensure the stability margins that make the aircraft fully compliant to the applicable regulations on stall demonstration and pitch control characteristics. This explains its inclusion in the original 737 MAX design.
These stability margins are required by regulation in order to support the flight crew handling of the aircraft during certain manoeuvres such as approach to stall …
MCAS was needed to provide full compliance but also that the loss of this function does not preclude the safe flight and landing of the aircraft; i.e. the 737 MAX remains stable following the loss of the MCAS function."
Boeing 737 MAX Return to Service Report
https://www.easa.europa.eu/sites/def...ice_Report.pdf