I am also trying to use the FTP server to manually sync scripts between my iPhone and iPad. I downloaded the script on both devices and had difficulty connecting from my Mac until I used the IP addresses instead of the device names. Not a big problem.
I was then able to drag scripts from each device to a folder on my Mac. The problem is that I can't upload any of those scripts to the other device to complete the manual sync.
It seems to be a permissions issue because the FTP "drive" is read only to me.