When I had corporate on the phone I asked them about this concept of "Mazdaspeed Certified" dealer service departments. They straight up told me they don't know what that is and have never heard of it. I have a feeling that any dealer that tells you they are "Mazdaspeed certified" is full of bologna and they are just attempting to gain your confidence in servicing your vehicle with them.
This definitely used to be a thing based on things like this and this. It's also mentioned here. However, I think that stopped being a thing by 2013. It used to be a feature of the dealer finder on mazdausa.com the last time I viewed it (probably 2014) but it's definitely not now. The dealership nearest my GF's place has just become a Mazda dealer within the last year and they do my 'speed oil changes no problem. They even think they know things about it - the service writer reported the tech told him that running synthetic oil would blow my turbo because it's thinner. LOL.
When the clutch on my Integra broke, the mechanics that drove it couldn't tell anything was wrong either. It was obvious to me. When they took it apart, a small piece of one of the shock-absorbing spring supports had broken off and was floating around causing intermittent issues. So yeah, it can be difficult to get people to understand that there's something wrong with clutch/trans sometimes.