I thought that I would be able to run a dove release business from a dovecote....... my problem was catching the birds as they were not contained in the dovecote. :-/
I do know someone who has little doors on his, with which he closes the birds in at night, that might be one option but, you will also need to devise a way of catching the birds when they return from a race. I don't see why you couldn't adapt a homing cage so the the birds can trap back into the dovecote but not get out.