Personally, Redox's use of URLs seemed like really bad design to me. It doesn't get simpler than the Unix path syntax.
Having a scheme:// makes sense for URLs because you don't otherwise have any contextual information indicating how to access a resource. But this isn't the case for something like a virtual filesystem, where the total set of filesystems mounted under it - and their types - are all known to the system. There's no need for disk://foo when you can just have /dev/disk/foo.
On *nix, you can always figure out what type of filesystem is mounted at a given prefix by typing `mount`.
What the use of schemes does is make things needlessly inflexible, and embeds a dependency on the name of a filesystem provider inside consumers of that filesystem. It's akin to a Unix where filesystems can only be mounted in top-level directories /mnt, but not /mnt/foo, etc.; I don't see the appeal.
Having a scheme:// makes sense for URLs because you don't otherwise have any contextual information indicating how to access a resource. But this isn't the case for something like a virtual filesystem, where the total set of filesystems mounted under it - and their types - are all known to the system. There's no need for disk://foo when you can just have /dev/disk/foo.