In the Metadata IPTC Template would be good to have the "plus" or "add" option that currently exists for some repeating fields like Keywords, and Persons Shown to be available on all repeating fields, or those specified as unbounded by IPTC. This means in addition to current fields that have that option:
Keywords
Persons Shown
Description Writer
Alt Text
Extended Description
It would also exist for:
Creator
IPTC Scene
IPTC Subject
Featured Organization Code
Featured Organization Name
Whether the plus was shown or not in the template could be customized via the preferences for users who didn't want to see them
