There is no solution to that one. Windows has no FUSE (there are other things, in various states of disrepair, but they are not FUSE). macOS FUSE is "special" as in it never really behaved like FUSE, and anyway is no longer open source, and Apple is actively preventing such kernel extensions from working so you essentially can't make your own / fix it at this time. FreeBSD has a semi-ok FUSE implementation, and OpenBSD has one that hasn't behaved well enough to merge support for it.
Walled gardens are not conducive toward being extended in this manner.
If you want to start a business that really hinges on this of providing virtual filesystems to these proprietary platforms, you better invest a lot of money into figuring out your tech stack. Microsoft & Apple really are not going to make it as simple as "grab an open source library and start programming".
Meanwhile, Linux just keeps working.