I think sleeping in nests is a bad habit that's best nipped in the bud. 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.