So image builder doesn't use datastore.upload, it executes import.vmdk. Just to clarify, it's about the directory name on the remote, or is it the `-folder=` (GOVC_FOLDER) option that you want to be able to set? govc import.vmdk takes a single directory name as optional 2nd argument, nested directories are not possible. By default it will create a folder which has the same name as the vmdk, without the extension.