Most shops will not service a regulator they did not sell. The Argonaut Kraken first stage is very similar to the US Divers Conshelf or Titan and services almost the same way. With that said, most divers use their own IP gauge every once in a while to check their Kraken and as long as the IP is staying between 130 and 140 psi and is otherwise breathing great then there is no real reason to service it.
Like all regulators the items that will wear the most quickly are the HP and LP seats. If your HP seat is failing you will get a gradual creep of IP pressure until it causes the 2nd stage to start free flowing. We have Argonaut Kraken regulators that have been in service for near 5 years that have not been serviced yet but there is no way to guarantee that any of them won't need servicing sooner.
Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB