That sounds like a good solution. I expect he'll move in with the hens at some point, but letting him choose is probably least stressful for everyone (you, him, them.) And when you do find him roosting with the hens for a few nights, then you can remove the crate.
Quote from your first post:
If you have time to watch, I would let him out near roosting time tonight, and see what happens--he may go in and sleep and be fine.
If it does not work well, you can stick him back in the crate and think about the situation some more. But it sounds like he and...