I think you should put a nest box in your coop even if it's along with the one outside of it. If there is light around from living in town chickens may get off the roosts at night to eat, drink, and lay eggs. When I leave a heat lamp on all night there will always be some off the roosts when I check but majority sleeping. Being in the middle of nowhere dark is dark here. I've had nights I literally couldn't see my hand held out in front of my face so without a light on my chickens stay on their roosts unless there's a bright moon. I would much prefer they laid at night. They are much more likely to lay in a nest box while in the coop than once they get out to free range the property. Some people purposely don't let their chickens out until noon so they will mostly lay in the nest boxes instead of randomly outside.