a) Engineering sims which hopefully have represented the aircraft well enough to fulfill their purpose in expedited development and certification (not sure).
b) Commercial full motion sims, that seem to have issues and program delays themselves which might just be another reason why mandated sim training was a no go for BA.
Was it because of the SW mandate and/or the simple lack of MAX sims?
I mean there are enough differences on the flightdeck where you really cannot use an NG sim.