My flame hawks have never messed with anything. Great fish. I have one arriving today. He will be going into a tank with a 4 year old pistol shrimp with a well carved out cave complex and a fire shrimp.They seriously do stare right into your soul! I have a pair and wouldn’t have a tank without them. I think I got lucky because mine don’t go after any inverts, they actually let my cleaner shrimp clean them. I assume that is what you mean by reef safeness
The only invert I moved in preparation was my pom pom crab. I am confident he won't get to my two big shrimp. I'll admit if I'm wrong also.