I don't know exactly what I have to implement to support SSHFS. But really in my mind a service like Reesd (or S3) is used through a networked API to read and write files, not through an exposed file system (although sure it can be exposed that way, just that it is not the "philosophy"). E.g. if you implement a music streaming service, you would access mp3 through say a REST API, not on disk, before streaming them.