Rated 4 out of 5 stars
Not all hosting providers allow https uploading and nobody should use unsecure protocols to send passwords. Please add support for sftp. Or save locally at least, then another script could upload file using scp/sftp/ftps.This review is for a previous version of the add-on (1.7.1).
I can only support protocols which are supported by Firefox. Sadly SFTP/FTPS aren't. Saving to a file will be possible in the next version. Also, there's support for HTTP Digest authentification which only transmits a hash of the password.