Luckily mine is a (dwarf) GSP, It's been 2 years with me and hasn't grown any, if it has it's not noticeable. It's more of a pinch with red marks than taking anything out. Probably because he's in defensive mode as opposed to eating mode. But I've learned. I have acrylic nails and pinch the krill with my nails and feed him that route. I feel bad he has to chase it all around the tank in the current.
One thing I love about puffers is they remind me of submarines
Just zooming around the water and quite and docile and then like a torpedo WHAM it hits something with force that doesn't seem possible.