LOL, I wouldn't even try to stop them. That's what we all strive for. Care to share what you did or didn't do to receive such phenomenal growth?
If you allow the orange colony to grow onto the substrate, don't cut/prop them right away. Allow them to cover a one inch square or so of the substrate then cut them away from the mother colony with a fresh razor, scapel or very shart scissors. Then glue 5 or 6 polyp clusters to a 2 x 2 inch piece of live rock ( rumble rock ) and sit them back in the same place and watch what happens. They may not take off right away, but they will once they settle back in.
Two thumbs up.
Mucho reef