Is mftp for cam_def implemented?

I have no problem fetching cam_definition.xml from an http server, but when I try mftp://[;comp=100]cam_definition.xml or mftp://cam_definition.xml, QGC does not appear to send MAVLINK_MSG_ID_FILE_TRANSFER_PROTOCOL msgid.

MAVSDK also fails with “URL using bad/illegal format or missing URL”

Has anyone had success transferring a cam_def via mftp?

Thank you very much!!