If it’s as annoying as you say, I don’t doubt it, you can always get another sync unit. Many people choose the option to have one sync unit for inside, and one for outside. That way you can run them on separate schedules. Many people have spare sync modules as a result of buying extra systems, as opposed to extra cameras, because there are often deals where a single camera system, including sync module, is cheaper that than of an extra camera alone. Often these spares end up on ebay, or similar, and can be had for a low price, whilst still being new in box.