I never say never, but this is a classic example of the warranty not being worth the price of servicing the regs. An excellent brand like ScubaPro or Aqualung (to name a couple) don't need servicing more frequently than maybe every 5 years unless you're making hundreds of dives a year. Even if you are, I don't service my Atomics (basically ScubaPro Mk20 clones) but when they need it, and I do make hundreds of dives a year. I understand how to use an IP gage, and service my own regs myself, but it's more to keep them O2 clean than it is because they need service.
I would never have a "service tag" on my gear. That's an invention by SSI to goad you into far more frequent service than you can possible need. I was a dive operator for the past 20 years, and will be again, and I never asked someone when the last time their gear was serviced. As Damselfish stated back on page 1, the only time we saw regulator failure was after service.
My wife and I are doing not much else right now aside from performing service for our LDS, as we are excellent at it, and they are not. We're waiting for our boat to come in, and when it does, we'll be back taking divers out. But I think we will continue to do gear repair, as most of the repair facilities out there are so bad.