I live in the Seattle area. There are a few dive shops who do reg service with their own techs, and the ones I contacted no longer do Dive Rite. There's one semi-local tech who was always the fall-back guy for shops who needed an assist with unusual stuff, and he no longer does Dive Rite either. This isn't a case of one shop trying to sell me a new reg set... No one I have called will work on Dive Rite any more.
One tech even called around to his buddies in the area and none of them were doing Dive Rite, either. The impression I get is unless these guys can order a big pile of service kits and expect to go through them, they are not interested in doing a one-off. And Dive Rite is not as popular here as it was some years ago, the last time I was diving.
I have not yet called every shop and I will make a few more calls before I have to make a decision. But upon contacting the top few busy shops the message was consistent: sorry, no Dive Rite service here.
Now you know exactly as much as I do about the local reg tech scene!