they don't have to give explicit permission though, they just have to not disallow it (which an EULA could do, in the US at least)
You're always going to basically be stuck asking for permission, which is the essential intent of intellectual property law.
One would not have copy the implementation. Just use the binary to understand how the hardware device works. Like "Aha, it sends point data as x/y/pressure triplets, each being 16 bit values" etc.