i know of fanciers who have 12 nest box's and 24 cocks and 24 hens in compartments either side, 12 pair get paired first then the next 12 pair , all enter the box section before and after training and of course on race day
not sure but you may have to flag them as they may be very determined to get back to the box section, plus from training you would need someone to part them as soon as they drop.
you can race 2 cocks to one hen and 2 hens to one cock on this system as well