I have a use case for SFFS where I have multiple local folders that move the contents to multiple remote FTP servers.
It's a way of easily sending data to remote FTP servers, just drop the files into the local folder and they are sent and deleted.
This works great, except for remote FTP servers that do not allow LIST. For these servers the sending and local delete work fine, but when SFFS is restarted it runs the profile entirely once and this profile run produces an error email, relevant bit here:
Error accessing folder ftp://ftp.host.com/: The system cannot find the path specified.
If I disable "Run profile entirely once" setting, files which have been placed into the folder while the scheduler was not running are ignored when the scheduler starts the real-time job again.