Hello, yep encrusting corals can be a pita if they get out of control.
I had similar issues from Pavona, i finally got the upper hand by using a dosing syringe & distilled water over heated in the microwave to just beyond boiling. Then i would fill the syringe & shoot fast in small sections literally cooking away the coral. Nice thing about this rout is no sliming & no contamination or coral spreading all over.
I would do it when the tank needed evap replaced that way the additional water actually helped also. It takes time, id do about 4-6" of an area at a time and some returns & requires a 2nd hit. If your tank is raising happy corals they can actually be a real bear to eliminate if they encrust. LOL.
I wish i had this issue with my Jack O Lantern Lepto but its the boring corals that do this. I also always replace the filter sock afterward to remove dead cooked debre tho it will not harm the tank.
You will be left with the corals hard calcium body that encrusted afterward hard to remove best to just coralline encrust over it. I was lucky it was on my rock not the glass or aquarium so not an issue, good luck!