  It would be highly unusual for the use of one pad material to interfere with the efficacy of another material on a standard metal rotor in such a way as to noticeably affect braking performance, particularly if the rotor were thoroughly cleaned beforehand. That's my opinion. There may be some kind of materials scientist out there who may know about something going on in the meso-scale that I don't who may disagree with what I just said, but I don't think so.  A