I think you could! Graft just provides transactions over sets of pages. As long as you can model your data in a compatible way it should work with Graft. A better question is how easy the system allows extensions to intercept filesystem operations. I'd prefer to avoid building a Fuse/NBD layer.

I've filed an issue for both:

https://github.com/orbitinghail/graft/issues/37

https://github.com/orbitinghail/graft/issues/38