Well, I was up at 2:00am this morning and 3 chicks have hatched. Two are yellow, and the third is black head to toe (I hope, taking on his BCM father's appearance). My brooder isn't quite ready yet, so I was checking threads about how long the chicks can stay in the bater without food or water. The consensus seems to be that they can stay up to 3 days.
But there was a lot of talk about using damp paper towel balls or sponges to keep the humidity up when the bator is opened, so I just had to experiment. The 3 chicks have pushed all the other eggs (36 of them) off to the sides of the bator. So, I opened the bator, removed the 3 egg shells from the hatched chicks, and moved the other eggs around to give those guys a bit more room, then replaced the cover. Elapsed time less than 1 minute, no sponges, no paper towels. The humidity had dropped from 75% to 38%, and the temp had gone from 100F to 83F. Within 1 minute after putting the cover back on, the humidity was back to 75%, and the temp was 100F again.
Now I am not saying I've caused no harm, but the speed that the Hovabator 1588 recovered suggests to me its unlikely I did...we'll see.