I have separate colonies for feeders and pets, (but no longer keep feeders as I don't have much to feed them to). And I've been known to OCCASIONALLY use "pet" species as feeders if their numbers are super high and they aren't selling well, to prevent overcrowding.
Other way around, I started keeping orange heads as pets but once they began exploding in numbers I started feeding them off.They also made a good waste system for any mismolted inverts since they are way more carinvorous than any other roach I've kept.