I always take the shells out of the incubator as soon as I see that they are fully detached from them.
I do not leave them in the incubator for long, maybe an hour or so at the most. As soon as I see that they have rested, have their little legs under them and start really moving around they go to their nice warm brooder where they have plenty of room to walk around and explore their new world. I don't think they are going to dry off with all that humidity either. I know that a lot of literature says to leave them in the incubator until they do but it's never been a problem for me.