The Dragon Maid manga is indeed still ongoing. It has a dedicated fan base and the creators are committed to bringing more exciting content. However, the release schedule might vary from time to time.
A great maid dragon fanfic idea could be a time - travel story. The dragon maid goes back in time to the era when dragons ruled the world. She has to find a way to come back to her present time while also dealing with the differences in the dragon society of the past. This could include things like different social hierarchies, magic systems, and cultural norms. She could also meet her ancestors and learn more about her own origin, which would add depth to her character in the fanfic.
One great 'Ms Kobayashi Dragon Maid' fanfiction is 'A New Beginning'. It adds a really interesting new adventure for Tohru and Kobayashi, exploring Tohru's past in more depth.
I'm not sure which movie you're referring to. If you can provide more context or information, I would be more than happy to provide you with more information about the movie.