I recently spoke to a good friend of mine who happens to do race car prep and also works next door to Scholar Engines. He told me both him and Scholar run engines in by running them gently for 15-20 minutes on a dyno and then using them as they're supposed to be used.
Basically don't hesitate to give them all the revs you want, but just don't apply too much load (e.g going up a hill in 5th gear) for the first couple of thousand miles or so.