Thanks. Good to keep in mind that duplicates in sets of two may be perfectly normal for sensor devices - i.e., because of Basic Set versus Notification messages. What I"m seeing is different - I'm seeing burst of multiple messages from switches and dimmers. For example, in the image shown below, there was a burst of 20+ messages all saying that a dimmer (Bathroom Toilet) was turned off.
As for the weak mesh theory - you've given me an idea there, I assume I can check the logs for each device and see if there is a small subset of devices doing this spamming and, if so, how many hops they are away, or if this is random. I think its random, but I'll check that tonight.
Note in this post: Z-Wave storms - looks like HE Hub's fault? someone did a Zniffer trace and found the hub was spamming the network with Get messages.
And, interestingly, I just noticed this: Spurious discovery frames [C7] which may be unrelated or may suggest there's something odd going on low-level.
