Rated 1 out of 5 stars
Just mount your server's share directory with sshfs, curlftpfs, WebDrive, and copy the file over with your bog-standard file manager, like a normal person and like it was intended.
Then the FileLink add-on part can be reduced to
In other words: Congratulations. You re-invented the wheel. *Badly*.
The intent for this addon if you have a hosting service or corp that provides webdav only. I really don't understand why you'd give this addon a bad review just because it doesn't match your use case and you'd rather upload the file using a different method.
The real question is, does this addon do what it advertises and does it do it correctly. There are users for this addon, if it were completely pointless then no one would use it.