FWIW, it's best to clean new rotors with brake cleaner of similar to
remove any protective "anti-rust" film that's on them.  Sometimes it's a
fairly thick sticky film that could interfere with initial braking
capacity.

From talking to my automotive tech friend, the omni-directional scuffing
is more to do with reducing harmonics when the brakes are first used
that actual effectiveness.  For some reason people hate noisy brakes.

Gregory Smith

Smith Design Studio
Small Building Company
Olympia, WA
360-239-0429
gregoryfsmith.com