Not many modders seem to have spent much time on 1.3. People did it for their personal modding, but not for the hosted mods type projects. It was fairly easy to see that 1.3 was badly enough flawed that it would not be a final version of the game and therefore was not worth the effort to update. Hopefully, 1.5 will be. It has a lot of potential. Of course, I've been saying that since RTW's release--this time I hope more of the potential is unlocked.