Yeah, I constantly have coral encrusting into each other. At that point, decisions need to be made on what I want the outcome to be. On a few occasions, I've just let some corals just take over others. But in the instances where I want the loosing coral to survive, I'll cover the invading coral's encrusting line with a 1/4" to 1/2' strip of coral epoxy. I'll leave it there for about a week to make sure it dies and then peel it up exposing the dead skeleton.