... for "Cliffs of Dover", the sim certainly needs one !!!
But it`s pretty useless to consider addons or campaigns as long as the sim is not working as it should and as long as it does not even have all the objects it should have and a fully functional mission editor.
Moreover - the sim only covers the time of summer 1940, how long can such a campaign then be ? 6 or 10 weeks ? That`s not even worth starting it.
Sorry