If you have AT&T service, can numbersync not be completely disabled (from watch settings, permissions, AT&T online account, etc.)? I have the 6.0.1 firmware and never see numbersync using the battery, but I've also never had AT&T service.
Correct you can you disable it and remove premissions but some times it still has battery usage for numbersync even through its not enabled. In some cases it will use 20% of the battery when not even turned on.