The “sync time” dialog box is silly. Who would say no? So why punish users with that disruption?
This also affects your best customers the most. Those with dozens of cams spend minutes scrolling through these.
My suggestion: Update time automatically over NTP and save the users the hassle of tapping yes.
You could make this a setting if you like, but i think it should be unnecessary.
Perhaps a setting to choose time zone and DST observance instead would help folks where their phone and cam are in different parts of the world.