Yo gums,
Boeing certainly have their hands full with the Max, but if the high stick-force trim loads are a dominant factor, then any solution, MCAS or not, might also have to consider other variants of 737.
I surmise that an inability to trim the Max with excessive trim loads (MCAS induced), will be compared to previous variant certifications which had to consider high trim loads because of Trim Runaway (also still applicable in the Max), which necessitated the previous roller coaster manoeuvre. If it is concluded that the practicality of this procedure is unreasonable for pilots fly in order to recover from ‘any’ extreme trim failure then the trim system may have to be rethought - e.g stop-down the range of trim movement, if able in comparison with the required certification range of trim.
Fixing MACS / AoA should address the deficient stability margin, but this most probably will not overcome the high stick-forces with offset trim - basic aircraft issue.