This sounds like a story about a saw that's getting pushed to detonation.
We set our 346's at 14,000 max and never look for the last 500 to 700 RPM's. I don't see any benefit to putting it "on the edge", and it won't cut any better at the limit anyway.
Setting these things must be done with a digital tach, and you have to know when you are up against a rev limiter. Usually when the tach reading starts jumping or freaking out.
Think about what you are doing here. Continuing to turn in the hi is leaning out the saw regardless of what the tach is showing. Be careful with your new baby.