My Setosa and Red Planet were about to go to war, so I laid down an epoxy border (was more concerned about the Setosa). Just below is a Purple Cross (another aggressive coral) that will soon meet up with the Red Planet. So will see what happens there. The frag at the top left can be moved so am not worried about it.
And mounted this little Red Planet frag just yesterday. It was an accidental casualty when I was laying down the epoxy. But today, I see all the polyps are out. It is less than 1/2 an inch, but obviously a tough coral.
A few days ago, I removed (and sold) my original Purple Cross mother colony. The stalk was more than an inch in diameter, and needed a hammer and small wooden mallet (am not joking) to do the job.

But it came out pretty cleanly, leaving only some growth around the bottom which I will leave in place. It was just too big for that location, and kept beating up on its neighbors, so it had to go. I have another one growing lower down (can see it at the bottom of the 1st pic), and is again growing rapidly. The Purple Cross is my original SPS (bought a good sized frag just over a year ago) and probably my most prolific coral.