I have a 2019 Raptor that occasionally makes a very slight rumble and steering wheel vibration at slow speeds with and without depressing the brake. I took it to Les Schwab yesterday for a brake inspection (63k on the clock). The technician told be the pads are all smooth and have about 6mm that remain. However the RF rotor has a grove cut into it and he could not determine how it occurred. He recommended the replacement of the front two rotors…..because they should always be replaced in pairs. He wants to replace them with “notched” rotors because the notched rotors dissipate heat “”much better.” I receive the repair estimate Monday. Could the grove in the rotor cause the rumble and vibration? Any feedback on notched rotors? Many thanks!