This forum is fine. I keep an eye on both for SHN questions. The EZX10RF will respond for each O/On segment it receives. Which Group (node from the ISY perspective) generates an Insteon message depends on the last House/Unit segment received. As you can see in my last post even thought the last house/unit code X10 message segment was several powerline messages in the past it still controls which Group (Node) responds to the House/Command X10 message segment.
I’m pretty sure this will turn out to be normal for the X10 message segments the alarm system is generating but no way to be sure without the X10 messages being traced.