The open source maintainers won't have the Windows source, unless it's given to them.
With enough patience and spit it should be possible to understand it. And AI can do it while we sleep.
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.