Good point and one I've mulled over.
Honest answer is: I've no idea.
However,unless you actually snap it, sharpen it or poke someone in the eye with it, its just a fire lighting tool, in a firelighting kit.
It has no sharp edges, just square ones, it's rounded so no pointy bits.
Context is important here, as is common sense, the same as with a knife. You have to ask yourself; " Why have I got this on my belt?" if you can't come up with an answer that is valid, then it goes in your pocket or better still, your bag.
Ultimately; the legality issues are debatable and not something
I can answer I'm afraid.
I'd say; you have a far better chance of convincing a copper that this is pretty much harmless, than
any knife,
including a pen knife.
The main motivation behind this "project" is to reduce the risk of injury when lighting a fire with a firesteel and I hope it covers that side of things quite well.
Mind you, the "blades" make cracking blanks for small carving knives and leather working tools
cheers
Steve