In OPC UA Pub/Sub (Part 14) the UADP mapping defines requirements around chunked messages if a DataSetMessages are distributed/chunked over more than one NetworkMessage. Have you discussed a similar requirement around the JSON encoding since common cloud message brokers have message size limitations. Or should this be implementation-specific details for the JSON mapping? The only statement I find on this in the JSON encoding is "If the JSON encoded NetworkMessage size exceeds the Broker limits the message is dropped and a PubSubTransportLimitsExceeded Event is reported"
Will you also publish a "PubSub AMQP JSON" profile at https://apps.opcfoundation.org.....Reporting/?
The JSON encoding is intended primarily for sending data to destinations that do not understand UA and would therefore not be able to receive an arbitrarily chunked message.
When creating a DataSet for publishing in JSON you need to ensure the broker limits are not exceeded by choosing fields carefully.