You did all you could, Frank. And the diagnostic charm is a sound indicator, so I believe you can set that one worry aside.

The blood magic seems the more looming concern. What might it empower Carrow to do beyond tracing the boy? And would killing Carrow actually free him? I have only the roughest, most general knowledge of what is possible with blood magic, but I fear that it deepens the tie between them. Certainly it Darkens the bond with which he holds the boy.

I'm very glad you did not tempt Fate and attack Carrow today. Who knows what might come of that now.