Yup if you are careful you can control it, you can take the arms that fall off and attach them to frag plugs and even bring them in to the LFS
if you wanted. The arms are also pretty easy to tear off of the rock, if you don't get it all though more will grow back. Also be careful when trimming any, cutting the branches will release some slimy stuff into the water so I would always do a large water change after trimming any.
It is basically impossible to kill this coral so don't worry about harming it. I've even read about a guy who took it out of his tank and put it on his back deck during winter to see if it would die, it didn't.