Missions are possible and fun to make, I am sure several foundry authors would click a submit tickbox to have a chance to have their missions be considered as actual faction Klingon missions!
Sure some people wouldn't, and that should be an option, on/off at creation. But it is such an EASY way of creating missions for the devs. All it needs is testing and balancing on the test server after that.
My mind boggles at why this isn't encouraged, giving great props to those authors whose missions make it to the game. This then could be done for romulans, cardassians and any number of mini factions after the klingon one is fully given its due. Plus honor those creators who make, put their names in lights and even give them special perks if you like , why not, they are helping you and the game/community! (last bit optional)