UDP Multicast

According to official product sheets, the RealPort and PortServer products support UDP Multicast. However, having read the manual, I get the impression that in this mode the Digi would just send copies of incoming packets to multiple IP addresses using IP. This is a far cry from “UDP multicast” as traditionally defined – i.e. the transmission to and from special groups which hosts can ask to belong to (on socket level).

What appears to be currently provided does offer the convenience of “real” multicasting but without the corresponding reduction in network traffic. Is there any way to achieve “real” socket-level multicasting at the present time? Are there any plans for such a feature in the future?