1) sometimes I see error writing to target file, but I think problem is with reading from file from remote SFTP server. Can you check that error reportings?
2) if connection is lost is not possible to continue. Usually I must exit from Total Commander and execute it again (sometimes it helps). Can you implement some (auto)reconnecting? It would be useful if connection is broken while copying ask user if he wants to retry operation and continue.
3) can you add some "Keep-alive" connection option?
can I download source code of this plugin anywhere? I can try to repair/update it
