Scrap Mechanic Mod is still being created to this day, even if the original is still under development. For the most part, they add new unique buildings. There are a huge number of them, both for those composed for the survival mode and for the creative one.
Not all of them are of high quality, of course, but they are all good. In fact, they are greatly able to facilitate the process of building objects for you. And even if you love hardcore, a thorough search is going to help you find what you need. You may be able to find the whole collection.
Believe me, downloading one will make it much easier and more fun for you. They are up to being some kind of instructions. And make your home more pleasant to look at. Or create amazing flying machines. In general, do whatever you want. Decide on your own. Maybe you are a person who is waiting for the final release?