Marc, since it's only 1 small coral that's affected (as far as you know), I'd put it in a separate quarantine tank and treat it "by the book" if you intend to keep it. I know you've had success treating an individual colony in the past, but this frag is completely covered with eggs and bite marks from flatworms. My opinion is that you would be placing your beautiful reef at unnecessary risk by keeping this coral in there. I'm not sure the treatment would be 'worth it' if you're only going to treat 1 coral, but I also know that you hate to give up on any coral and, philosophically, it may be the right thing to do. Nobody would fault you for throwing it out, however, and considering the labor involved, that would probably be my personal course of action.