Deadline Publish job pass along additional metadata for custom addon

Is there any way, without changing Deadline plug-ins to pass on extra metadata to the instance or representations that the SubmitPublishJob generates and hence the publish job on the farm also reads for the instances or representations.

I want to add some extra data to the instance or representations, (e.g. an additional tag or something else) and then with a plug-in respond to that on the publish job.

Like:

  1. User allows to pick a setting in publisher UI to post-process the render (either after local render, or on the farm)
  2. Their chosen option should be passed on to the metadata json so that the publish process on the farm can use it for its processing.

Preferably there would be some custom render data that the publish job would passing along, e.g. instance.data["renderMetadata"] = {} or some other reserved key that it always passes along so that other addons can put custom data in there without having to customize ayon-deadline itself.

Reference

Any ideas?