Just to let you know about the WOT method - don't do it!!
I have 2 OS VZB'S both new from the same shop. I ran the first one in by the first method you desribe. This engine is now on its 3rd gallon and it rips. No wear on th rod. The only additional thing i did was warm it with heat gun whiel running in.
The 2nd one i heated up with the gun, ran 1 tank at idle then 6 at WOT. After that tuned for performance.Sunday this engine snapped the rod with less than 1 gallon on it.
i know which method i trust at least with the VZB's. I also ran my RB in this first method way and thats fast as well