A technical point which I may have missed: with the stick full back, MCAS remained active, but the main electric trim is disabled by the lower stick cutout switch. In this condition would any pilot stick-top trim switch have any effect in moving the trim?
One version of ‘the drill’ required re-trimming before isolating the trim system; if as above, this would not be effective if the stick was already full back - MCAS failure.
Thus for any abnormality where the stick is full back, then the pilot cannot reduce stick force with electric trim - revert to manual wheel trim - if able, spare hands and difficult to move.