The screws in question are 4.5 x 30mm A2 stainless steel hinge screws. As far as I can tell, they are good quality, branded (TIMco), double-countersunk, manufactured by thread rolling.
Material is hardwood (oak) with 2.5-3.0 mm diameter pilot holes, so a high index of friction.
A drill clutch would constrain the max torque to an adjustable limit, but in this case it was decided to fit the screws manually given the size of the screwheads relative to the hinge screwholes.
Given that one can usually deliver several times more torque using a T-handle screwdriver than a normal screwdriver, is there risk of screws like this breaking when handled this way?