piston rings need an amount of abuse to bed in - and then need continued hard use on a regular basis for them to remember how to their job...
so many ideas on running in, if machined OK then the old world very gentle wear off the rough bits should now be history - early CX500's were the last with clearly the wrong sized mains and big ends - where some owners just coped or others self destructed early on.
temps on high spot is an issue, so running in all at once with high loads and temps is not as clever as a number of 25 min runs where after warming up to up temp, allow to cool for 20 mins, then gentle bit of ragging, then let go fully cold should end up a better way
its more how hard you worked it at the wrong point that will drive excessive wear - won't do much harm to keep the first 300 miles gentle with varying revs and light load, cool a smidge then bit of proper exercise before you park up each run to bed the rings nicely
on a two strokes motocross bikes with roller bearings (that don't really need to run in) - the fast boys used to do a gentle warm up, rag to death for 30 to 60 seconds - allow to go cold - do that three times all done....
one should never forget I think all factories do full power runs before you ever get the bike