At least that's what you get for free, and if your sFTP server only is capable to support sFTP (perhaps even SSH over FTP?), then that's that. For Website management, you typically have several choices. The topic is secure file transfer, isn't it?
If you want something free acting via SSH File Transfer Protocol PuTTY or OpenSSH would be clients to use via command line switches, perhaps. I only used PuTTY manually and locally when the company I worked for then had some Linux Servers, not from VFP, but I know it has command line switches and would offer this more legacy way of automation. Create Batch Files and run them, pipe output into files (eg directory listing) and read them with VFP.
Or go with the Chilkat Activex components.
Bye, Olaf.