An option in the BulkAttributeRemover to remove Unexposed attributes only would be useful.
Some transformer eg.: JSONFlattener or JSONFragmenter create all new (potentially unknown) attributes, even though usually the exposed ones are used only - which may be excessive. Now the exposed attributes must be (bulk) renamed before bulk removing the unexposed, but prefixed attributes.
An alternative way would be adding a “create Exposed attributes only” option in these transformers, so they wouldn’t even create unnecessary attributes..