Mansfield
The two ANU trim inputs shortly before the end indicate that a) the master trim switches were back on, and b) the trim motor was capable of moving the stabilizer. I really don’t know whether the manual trim can be frozen while the trim motor still works, but I suspect it would be the other way around.
Just a minor technical point. If a heavily loaded jackscrew cannot move in the nose up direction, that does not mean it cannot move in the nose down direction. Consider the case of a scissors jack under a heavy vehicle, and you get the picture.