So glad your roo made it home. Wanted to mention the trick my husband came up with to gain some control over our chickens, in case you wanted to develop something of the sort to work with your roo.
Whenever we give them their favorite treat, mealworms, we tap on the plastic container, so they now associate the sound with the treat. Then when we need to get them back into their pen, we tap on anything plastic, and they come running. (You would probably need a louder sound with your space.)
He's tried getting them to associate a finger-snapping sound with the command "no", but that one isn't going over so well. Don't think chickens know the meaning of the word "no".