WOW! Jim, it's a good thing I didn't have to go through what you're going through to build. I'd be dead or in jail facing homicide charges.
It just doesn't make sense that they are making sprinklers a mandatory part of your addition. And at this late date? Smacks of whoever thinking that if we spring this on him too early, he'll take us to court.
While sprinklers are a great tool to help fight fires, many great thoughts have been brought up here, as to why they shouldn't be in individual homes. Is the township going to phase out their VFD?
Here's a thought though Jim. As you stated there are some high $$$$ homes built that didn't have to have these sprinklers. I'd start investigating and while you may not have the time right now to do anything about these sprinklers, perhaps in the future you could sue to recoup the money spent on installation and maintenance.
Hang in there and keep us updated.
Karl