I have never heard of arbor damage from a brake activation on a dado stack. I believe Sawstop's recommendation is more concerned with the brake detection and activation. From Sawstop's webpage of Frequently asked questions, "SawStop recommends only using 8” stacked dado sets, with a maximum thickness of 13/16”. “Wobble” dado sets are not recommended, as they may not engage correctly with the dado brake cartridge. Do not use dado sets with solid-plate interior chippers or blades with molding heads, as neither brake cartridge is designed to stop those blade types."