Final puzzle is why only brief trim inputs after they re-enabled trim.
I think ( but not sure and wait to be corrected ) what the FDR data published shows is 2 briefs trims movements , .If this is the case , it does not show the actual inputs physically made , it could have been a continuous trim input by the Capt but it only worked twice briefly , possibly because the aerodynamic load on the stab was already very high ? just an attempt to understand it . I do not think the actual trim switches positions are recorded , but as I said, waiting to be corrected .