Having a Linux client is desperatly needed. Even if it was just a command version with no UI, you have to do it all through terminal would be better than not having one at all. Even if you had to redo everything every time, and didn't do incremental backups at first. Get like a super alpha that basically just uploads the files selected to the datacenters.
Obviously getting a UI would be good, but not needed at first as most Linux users can operate fine in terminal.