The remote backup features in terms of SFTP and SSL-FTP are really overdue.
We discussed some parts about it already in
Remote Backup via SSL and with encrypted archives
Some feature requests are nice to have but an encrypted transfer out of the box should be a must have. Since the account transfer routines already use sftp I still wonder why unregular account transfers can be encrypted but regular backups can't (out of the box).
SSL FTP in terms of speed would be better, but to take the ssh codepart of the account transfer routines and implement them in the backup routines sound like a good start for 11.25.