How do you choose a 3D metrology service provider? (medical procurement)

I'm in procurement for a medical device manufacturer and we're looking to outsource some inspection work to a 3D metrology service provider. This is a bit outside my usual wheelhouse, so I'm trying to get my bearings before I start reaching out to vendors.

For those of you working in metrology or who use these services, what should someone in my position actually be looking for? From a technical standpoint, what separates a solid provider from a mediocre one? Is it specific certifications, equipment capabilities, industry specialization, or something else I'm not thinking of?

Also, if you've worked with providers you've had good experiences with, I'd really appreciate any recommendations. Just trying to build a solid list to start evaluating.

Thanks in advance for any help!