ok re: duck and chicken eggs, I would take the turner out and hatch in egg cartons to keep the hatching chicks from playing soccer. the duck eggs (also in a carton) will survive a couple days not turning.
but I've heard of chicks getting stuck under the turner and squished because they couldn't get out and it kept turning. just my 2c, but it's easy enough to get humidity back up quickly, line the floor with paper towel, add hot water to the paper once everything's in place and put the lid back on. the water will evaporate from the paper towel pretty quickly and should go back up to where it should be,