I am not disagreeing with the above, I have built many engines, however I will never proclaim to be an encyclopedia nor a professional engine builder. Also the info on the internet can be somewhat muddied at times.
He should have a plan especially for the run in, taking into consideration the engine characteristics, including but not limited to, honing, type of pistons, rings, clearances, squish, bearings etc etc etc
At the end of the day, you did ask for run in oil and you have your answer... :lol: