If you're comfortable with creating your own JFBConnect Open Graph plugin for Cobalt CCK, that is the course that I would suggest.
There are several different ways that JFBConnect sets the Open Graph tags on the page, as described at
www.sourcecoast.com/jfbconnect/docs/open-graph/tags-for-joomla and gives different priorities to each of these. From highest priority to lowest:
1. SCOpenGraph easy-tags manually inserted into content. e.g. {SCOpenGraph description=blah}
2. Our Open Graph plugins
3. Default option in JFBConnect > Open Graph > Configuration area
4. Auto-generated tags based on metadata for og:url, title, description, type, app_id, locale, site_name.
If any of the tags are set by a higher priority in that list, they won't be reset again by JFBConnect. Therefore, if you create the plugin, any attempt to auto-generate tags won't be done for the tags that you've set in your plugin. If there are any in #4 that aren't done by your #1-3, JFBConnect will still attempt to generate.
-Melissa