In my experience most companies that have put any thought into this will mandate that on any go around you should accelerate at MAP Atlitude.
Unfortunately, Mr. Boeing in his FCTM says words to the effect that during training an acceleration altitude of 1000 ft. AGL will be used. This statement has muddied the waters and is used by some as justification for a 1000 ft. acceleration. I think this was just ass covering by Boeiing. Fortunaltely we don't do many go-arounds, especially with engine(s) out, or we'd see the headlines resulting from this folly.