From a
presentation of 2019-09-03 by EASA's Executive Director Patrick KY, as posted on the European Parliament's website:
IMHO, "
Too high forces needed to move the manual trim wheel in case of a stabiliser runaway" is technically challenging. I can't see an easy fix. At best, software can make stabilizer runaway extremely unlikely. Training can improve recovery to a degree (see the
Boeing advice on "aerodynamically relieving airloads" using manual stabilizer trim thread), but subject to altitude constraints.