Probably age related, but I'm uncertain if I posted on this, but it is my strongly felt notion that any runaway trim, detected by a black box and/or the pilots, should be stoppable by one very accessible master warning switch. It could be made to cut all four inputs which could be reinstated one at a time with age-old diagnostic logic. Main power to the DC motor. Functionality of the Electric thumb switches. Autopilot. ECAS. In that order.
I just don't think training pilots to be aware of the authority of the electric thumb trims is sufficient - and that's assuming the right cut-out switch is returned to NG logic.
A divided four channel system may seem over complex but we're talking about resolving one of the most serious issues to hit modern aviation.
Such a warning and easy access cut-out would stop an ultimately powerful flying surface in a realistic time, and with utter crew awareness. Grabbing at wheels - even rubbing at them with one's shoe to save burnt skin! For heaven's sake, we've had the whole gambit of absurd suggestions for overcoming a bad design that's been festering for decades.
Then there's the issue of the force needed to hand crank the Stabilizer. I've little doubt it would be easier to implement the above proposal than move the electronics that caused the reduction in wheel diameter. Even with that cranking radius restored, it was still a challenge to turn. Toronto comes to mind.
It occurs to me that the Stabilizer fulcrum would not have to be modified to forward-of-centre (trailing) position. A small change would make a vast difference to the load. Still a major modification, so in the real world I guess powering the cable-run is probably the only cost-acceptable method - but as soon as it ceases to be truly manual, the whole ethos of Boeing's retention of that manual system is to a large extent negated.