Welcome aboard to the HiveMQ Community! It’s fantastic that you’re interested in MQTT and the HiveMQ broker. We’re thrilled to have you as part of our community.
Regarding your question – it seems there might be a slight confusion. The <use-schema-registry> parameter is associated with <kafka-to-mqtt-mapping> rather than <mqtt-to-kafka-mapping>. This means it pertains to the data the broker can receive from Kafka, rather than the data it sends to Kafka. Let me know if you need further clarification on this.