You would actually be surprised with how fast a 10" porcupine puffer can move. I hand feed my big cowfish and Griff wants his food. That puffer can move at light speed and almost come out of the water if I take the food out.
He is the biggest fish in my tank, and I have to say he has no interest in nipping fins. The only thing he ever nips at, is stuff he can fit into his big mouth, like smaller clownfish, which I don't have anymore. He has no interest in eating any of my shrimp or anything other then what I feed him now.
Porkies can move with full afterburner... you have to see it to believe it. I don't know much about the particular fish you are asking about Laurie, I hope you get some answers.