you can move them as long as you have a place that mama will feel is safe. My hens have all hatched eggs 2-3 feet off the ground. I keep a thick layer of bedding in the coop so there’s lots of cushion if they fell or jump. But mama is also able to tuck the babies under her wings like they do with eggs and transport them. It’s common in the wild for mama to hatch and then move everyone to the ground once the chicks get to moving around a lot.
If you have the space, leaning a 2x6 up to the box can work as a ramp for them as well.