I'll partially dis-agree with those statements.
Half to two thirds of maximum capable rpm / speed should be observed for at least the first couple hundred miles.
So about 60-65 mph in top gear.
But it is good to use full throttle & short shift thru the gears to get up to speed. Putting a 'load' on it but not forcing maximum rpm is what seats the rings & polishes in the cylinder & piston. Over-revving can scuff the brand new piston.
Revving a brand new engine to the maximum is never good.
85% of piston ring seating occurs within the first 15mins of run time. The remaining 15% takes a good bit longer.
One shouldn’t ping a brand new engine off the rev limiter, but giving it a good & hot workout will ensure minimal oil usage during the lifespan of an engine.
I’ve also spoke with engine builders who follow similar break-in procedures on “engine only” dyno’s. After a half-dozen 2/3 throttle runs, they’ll change the oil & let it rip after that. This is all done with less than 1 hour on a brand new or rebuilt motor.
If it’ll work on a $20,000+ race engine, it’ll do just fine on a KLR 😂
Everyone has their own break-in flavor. Do what you think is best 👍