Possibly as workaround for now, upload via the existing interface, then:
https://<fwd1|fwd2>.mios.com/<user>/<pass>/<serial>/data_request?id=lu_action&serviceId=urn:micasaverde-com:serviceId:HomeAutomationGateway1&action=RunLua&Code=os.execute("mv /etc/cmh-ludl/<filename> /usr/lib/lua")