I have successfully applied the new OTA firmware version 1.0.5 update (via Zigbee2MQTT), then paired it back to the home automation system where the ZBMicro is used (Hubitat).
Now, the ZBMicro sends Zigbee messages (ZDO Match Descriptor Request) to the hub only once every 3 minutes (180 seconds), as many other Zigbee devices do. Before, the request was sent every 15 seconds. With this update. ZBMicro is 12 times less chatty than before! 
Thank you very much!