I do not let mine free range until they start to roost, that way they come home before dark, just watch for vermin.
I would let mine free range from their tractor when they were little. I put 2-3, 2x4s under one edge and let the chicks crawl under. This did two things it allowed them to come and go from the tractor at will, and most importantly it allowed me to feed them and not have the other chickens get at it. I gave the little guys food at sunset and they would run in to get it, then I would remove the 2x4s. Once in a while I did have to run down the fiercely independent one.
I wanted to give the babies a place to get free of the bigger chickens incase they were over bearing. It worked well.
I have not found CX's to be much for roosting.