The way I see it is, having a certification doesn't hurt, but it shouldn't have as much weight as real world experience, natural talent and a consistent history of excellent results to back it up. I just looked up some info on the CPCP, and it states on their website "Certification is a formal recognition of comprehension of a specific body of knowledge demonstrated at the time of the examination."
So someone having a CPCP cert tells me that they're good at memorizing info and ability to pass an exam and should be somewhat knowledgeable about the domains related to permanent cosmetics. Nowhere does the certification require a minimum amount of experience or endorsement from a certified/experienced technician or board of professionals.
It's the same case in the hair transplant industry. It's like going into a HT surgeons office and expecting him to be knowledgeable and serving your best interests because he has a "Doctor" title but how many people have been butchered from surgeons with this "Doctor" title? So my point is if a "Doctor" title doesn't prove natural talent and a history of excellent results, "CPCP" doesn't prove much as far as a SMP techs abilities.