Custom deduplication mechanism base on x-message-deduplication is great but in common cases we not always to be able to control the source side (like using a service that support sinking to rabbitmq) and all we need for deduplication is just the payload. So I think there should be an option that the exchange will automatically generate checksum (hash) base on some configurable properties and it's the payload by default.
If the plugin can support a param let's say a regex to standardize payload to generate hash, it will be more generic.