15 Thread messages per second sounds like a lot at first glance. A good mini-PC running Home Assistant with a dedicated Thread radio would probably not care much from a CPU point of view, but the Thread radio network itself is still a low-power mesh network. At some point, the available airtime and reliability become the limiting factors.
But I do not think it is normal for a regular Matter device to generate that amount of traffic by itself. Even an Eve Energy plug with power measurement should not constantly flood the network. In normal use, measurement reports should be sent when there is a meaningful change, or after a defined reporting interval.
So the more important question is: what kind of communication was actually measured?
Were those real application-level reports from the device?
Were they Thread routing messages?
Were they retries because acknowledgements were not received?
Was the device repeatedly trying to establish or repair routes?
Could the multiprotocol design be missing too many packets, causing retries and additional traffic?
In other words: the high message rate may not necessarily be the original cause of the problem. It could also be a symptom of an underlying reception, acknowledgement or routing issue.
Without blaming anyone, it is also possible that Homey itself, or Homey’s Thread implementation, contributes to this traffic. For example, if acknowledgements are missed, devices may retry. If routing tables are unstable, routers may repeatedly try to discover or rebuild routes. So before concluding that the device is simply “too chatty”, it would be useful to know exactly what kind of messages are being counted.
That also leads to another question: how would a user setting for update frequency actually solve the problem?
If the setting is not applied directly to the Matter device or to the subscription/reporting configuration, what happens to the messages? Are they dropped? Are they filtered inside Homey? Are they queued and delivered later? Could this introduce delays of several minutes, or hide the real issue instead of fixing it?
From the outside, this looks less like a real fix and more like damage control. It may reduce the visible impact, but it does not necessarily explain why the traffic is so high in the first place.
