As a long time twin engine pilot, with regard to whether or not to carry out a Cat A departure, I see no reason not to minimise personal risk irrespective of legal requirement, to save a few seconds.
In any case, a smoothly flown Cat A puts less strain on the transmission than does a maximum power pull departure. It also allows me to reject forwards and down visually back to the departure point far more easily than a trying to descend onto it vertically. There might well be reasons other than engine malfunction to reject.