How do you handle a staggered hatch with dry incubation?

So I set quail eggs and chicken eggs together. The quail eggs will hatch about 3 days earlier than the chicken eggs. I am suppose to add water for lockdown for the chickens then. Do I do it earlier for the quail eggs? Will this potentially drown the chickens? Should I just not worry about raising the humidity for the quail? Also I set 20 eggs but only 7 are good. If I wanted to start some new eggs how does it work once the first set of eggs hatch? They make such a mess and get smelly. I can't clean the bator when the eggs are cooking. Do I need a second bator for hatching? That might solve my other quail egg problem too. Of course I don't have a 2nd bator which might be a problem! Lol!
Thanks!