A small nfs server that can provide access to Rclone mounts. Since Rclone supports mostly all cloud providers and remotes you can expose these files and remotes via nfs.
This is a neat hack, thanks for sharing it. While researching in this area I noticed that support for rclone serve nfs has been recently added to rclone itself, so I guess it will be in the next release. Thought I'd mention it here in case it's helpful!