FYI, the centralized content manager does not add replicas on import. If you know a bit of HTML and JS and want to have something like a label that is updatable across all courses, just go into the HTML and give the content a unique id or class name and update it with a script from the Additional HTML page. You can also do it from an external script that is imported in the HTML of the content you want to dynamically update. Doesn't work for settings like the CCM does, though.