Discussion of control forces makes me think about the second level of MCAS, where the authority was increased. Theory follows:
The stabilizer can overpower the elevators, as we know. It can also move into a position where the pilots physically cannot pull hard enough to get the required elevator deflection, or wind back the nose-down trim.
So while MCAS was originally designed to smooth out a bump or dip in the stick-force-to-alpha gradient, it evolved into a system that can block the controls and prevent the aircraft from entering a certain corner of the envelope. In short, a full-authority envelope-protection system.
And that's why a single-channel system was a disaster, and why a dual or pseudo-triplex system can't be certificated.