webdav middleware

[Raphaël Droz]

The two file-transfer protocols natively supported by all OS are FTP and webdav.

Other protocols are either outsourced to intermediary proxies like
- https://github.com/hironobu-s/swift-sftp
- https://github.com/hpcloud/swift-webdav
- https://github.com/cloudfs/ftp-cloudfs
either is the support delegated to clients like Filezilla or Cyberduck to name a few.

Some OS providers choose to support sftp as part of their offer: https://docs.ovh.com/gb/en/storage/pca/sftp/

Given that Swift has been able to support a good S3-middleware, is there any fundamental protocol-level issue blocking the apparition of a swift-webdav middleware?