Reading through the DPDG, sections 2.4 and 2.5 on evaluating sample data products seem like a good place to formally call out any role that service development teams would have in evaluating the interoperability of data products during the design process. (Example services including: OPeNDAP, Harmony, EGIS, etc)
This would likely have to follow on from such roles being officially defined, but this seems like the right spot to call out what that should look like once we know that.