Thank you, Zigbee2MQTT devs also refers it as firmware changelog - EmberZNet adapters (Silicon Labs) | Zigbee2MQTT, so seems to be combination of SDK and also relevant chip firmware modifications.
(it’s just complementary info however I don’t think Athom will ever soon go new version 7.4.4.0 released in August but the changelog for both 7.4.3.0 and 7.4.4.0 is quite comprehensive)
