This topic is of much debate & discussion on moto forums (rice-rockets). The general rule of thumb from racer guys who build motors is to do a series of accelerations working up to redline the 1st time you drive (ride) it. That's what I did with my R1 and it [still] runs like a champ 7 yrs later.
Ram undoubtedly red-lines all motors at the factory after they're build to ensure they run well and nothing falls apart.
The varied approach seems to be popular - that's what I plan on doing.
I think you'd be fine towing something with only a few hundred miles on the motor. If it has oil in it, I think you couldn't ruin a new engine if you tired. (not that I'd volunteer to test that