I read this again. Seems your worried about the chooks using the nest boxes so your thinking that leaving them locked up longer & with a light on will ensure that they will lay in the boxes. Here's what you do make sure you have pine shavings in the boxes & a fake egg in one or two of the boxes. Let the chickens handle the rest. They know what to do trust me. You don't need a light my electric bill is high enough with out turning lights on for the chickens. I have 7 coops could you imagine lighting them all up. I'm not thats a fact. Let your chickens lay when their ready. Its better that way.