Major Erik Paulson - mqtt-comment
In looking through the 5.0 MQTT draft, is it possible to put any user properties on a subscribe request? The use case I was thinking would be for in broker implementations if you wanted to pass some additional data along to give hints to the broker, e.g. for something like Kafka "start my subscription at point X".
It could also be useful to carry along additional authorization metadata, instead of only being able to use whatever authentication was established at connection-time for authorization. It might be nice to slip in a bearer token to a subscription request and use that for a specific topic.