Maybe I miss the point here, but to me, it seems that the MCAS is a device intended to keep the aircraft below a certain critical AOA and, therefore, in essence a stick pusher.
Now, Stick pushers have been around in many aircraft types, jet and prop, of eastern and western provenience, since the mid-1960s and seem to be a well understood and safe system. They are known to the crews operating the type, they rely on at least two separate AOA sensors and they can not only be cancelled via a prominently placed push button but also be overpowered by the crew in case of undesired activation.
With the type in question being fly-by-wire, why is it not possible to introduce a stick pusher software that introduces the required nose-down input not via the stabilizer trim but via the elevators and can be cancelled, if so desired by the crew, via e. g. a glareshield-mounted push button?