I, personally, would love it. Logistically, it does kind of seem like a nightmare, though. I started out as a waxer, but after a few years in the industry I developed problems with my hands that was threatening to end my career in the field. I was very fortunate to be able to transition into CAD/CAM when I did. I had thought (briefly) about pursuing a CDT in C&B, but I also have metal allergies, which has kept me away from ever attempting to metal finish.
If a CAD/CAM CDT were an option, I guarantee you I'd be all over it. I have a few vendor-specific certifications, but I feel like I'll eventually hit a ceiling. It would be nice to have something more universal to express my qualifications, that would be recognizable across the board.