I've got some free ranging cornish x's at the moment. 10 weeks old and about 3 weeks behind schedule, since they are like only 5-6 lbs. They HAD their own coop where they could gorge themselves fat so I could eat them, but no, when I let them out, they decided to team up with the 13 week old leghorns from a different tractor and submit themselves to being pecked on and abused by the layers by sleeping in the layer coop by choice instead of their own. :rolleyes
They really aren't that bad when they force themselves to be on a diet and try to do everything their leghorn role models do... boy it is funny to see them try to "panic" and fly over fences but hit like a rock 2 inches from where they started instead.
Good luck with your dual purpose birds. Nothing wrong with eating a scrawny bird, it's more native form is actually desired in some cultures.