I see. I think it would be a good idea to have a filter that lets powerusers modify/add/remove functionality in core fields.. I’ll notify Elliot of this and we’ll see what he says!
In the meantime a solution (albeit not a pretty one) would be to “hardcode” the information on a per field basis using this hook:http://www.advancedcustomfields.com/resources/acf-render_field/