As time has passed, I have been trying to understand how the PLM will present commands that are sent through the Insteon network. Through testing I have discovered that there are no commands received by the PLM for any device or group that is not linked to the PLM.

To overcome this limitation, it is necessary to link all controllers to the PLM (PLM is a responder). While it is only necessary for one controller group per device to be linked, by linking all controller groups, it guarantees the message gets sent to the PLM.