I sometimes feel uneasy about the Boeing advice not to take action on an engine fire until at least 400 feet after take off. This seems to imply that an engine fire in (say), a 737, is no big deal.
With a engine fire warning at V1 at a WAT limiting take off weight, it could take some time to climb to 400 ft particularly if for some reason the gear is not retracted immediately. By this I mean a PNF forgets to call positive climb and the PF is so used to hearing positive rate that when it is not verbalised he instinctively fails to call gear up.
The worst I have seen in the simulator is around one minute of fire warning before the crew take the first recall action. It seems that a dangerous false sense of security is engendered by strict adherance to a Boeing SOP that is more concerned with the possibility of wrong identification than extinguishing what may well be a blazing out of control fire.
Unless the crew get visual confirmation of severe fire from the cabin crew or outside observers, it is probable that the crew have no idea of the severity or otherwise of the engine fire. After all, all the crew can see is a red light on a fire handle and they would not know if its an itsy bitsy fire or a roaring inferno.
In the simulator I have seen the PNF have writers block when directed to carry out the recall items for an engine fire at V1. In one case the PNF hesitated an inordinate time because he was trying to remember in time of extreme stress whether the first recall item was throttle closed then auto-throttle disconnect - or the other way around. Meanwhile the PF waited impatiently while the fire burnt away vital bits and pieces. Very worrying.