Just follow the owner's manual, it's really that simple. Problem is, everyone seems to have their technique or heard this or that, but at the end of the day, simply put it's unquantified, unreliablehearsay.
As much as it would hurt some people to admit, the manufacture know best, as they've built the friggin thing, no some random internet ABC part time mechanic. All this talk about "well it's written by lawyers, the first xxx is it" is bull. Anyone who says this, please explain the science and research (pre and post) on engine degradation you've personally done. If not taking it over 7000rpm the first 600miles is bull, then why wouldn't Yamaha keep this handicap indefinitely?
I'm sorry, but every day I got to work, the combined value of the engines of the vehicle I drive is worth 60 million USD. I assure you, any limitation the manufacture lists is followed down to the letter. They don't screw around, simple as that.