i don't think Kunzite/Zoisite added more to their characters because honestly i don't think of their anime counterparts even being the same characters.
i MUCH prefer manga Zoisite especially.
and of course it seemd tacked on and underdeveloped, she never got a chance to add it in and develop it. i understand thinking it would be "too perfect" but in defense of the author, we don't know how forced it might have been or how awesome it might have been too since she never got to do more than one promo picture.