Groove in CCB Rotor, should I worry?

[nickl630]

Couldn't find any specific info about this, I took in my F80 to get looked at for a similar nose (vibration under light braking/turning... feels like a wheel rub it its not. They said it was normal for CCB's)

I noticed this when cleaning the car yesterday, being that CC Rotors dont typically "wear" the same way as traditional discs I wanted to make sure everything is on the up and up. Would you have the dealer check it out?

Edit: doesn't appear to be any debris or rocks on the pad, but I haven't removed them yet.