Never confuse 'Normal" procedures with non-normal (emergency)events. In the case of an engine failure you do what is necessary. If you only need normal thrust to remain airborne, fine. On the other hand, if 'radar thrust' is required (where you shove the thrust levers through the radar), use radar thrust. This is, of course, for jet engines. Recips tend to be much fussier and more demanding.
But the focus shifts from normal temps, limits, time to getting the airplane safely back on the ground. More often than not, normal limits will not be exceeded but the mindset has to be changed to using whatever is required to be successful.