I think sleeping in nests is a bad habit that's best nipped in the bud.I have tried moving them. so I guess the better question is, is there any reason not to let them snuggle in the boxes? Personally I don't care about the clean up aspect and they aren't laying sooo...no harm no foul? pun intended LOL
You might not mind cleaning nests now when they are not laying,
but cleaning poopy eggs might not be so cool,
and by then the habit may be much harder to break them of the habit.
I cobbled a permanent hinged cover over my nest bank, every year I have this problem with new groups of young birds. Last year to took 8-9 weeks for them to get with the program, this year only 2 days and they were on the main roosts with the bigs.
It's easy to flip it down an hour before roost time, then flip it back open after dark when I lock up.