600 miles is a real safe zone for break in on a scooter. It really only takes a short while to properly seat the rings. The idea is to wear the outer ring edge into the bore. There are micro scratches in the bore (cross hatch) and the purpose is to wear the rings into an air tight seal. Gases go BEHIND the ring, and force it out onto the cylinder wall making that seal. If you just hammer the bike from new the gases will force over the seal side preventing "break in" and causing "blow by" for the life of the ring set. This causes carbon to build on the sides of the piston slowing down the rpm, and creating excess heat in the jug. I use 250 as my "target" break in. around 100 miles the rings will get quiet, and the rest is really just polishing.
Further down the road if you need fresh rings the seating is almost immediate. A fresh hone, new rings, and 50-100 miles is done.