and can fit other nearby tiles automatically.
The example scripted tile from Unity has some automated tile placement, but they are crude and not very user friendly at the moment. You have to customize it heavily to make it for case by case. I wish Unity spend a bit more time to give us better Editor script to deal with scripted tiles. At the moment, there are only few of them and not generic enough to be set up to fit the specific needs.
We intend to provide more scripted tiles in the future, as we keep developing tilemap.
Thats good to hear. There is one thing good about the current state of the scripted tile map. It kinda forces you to make your way into researching the algorithm behind it and now I have much better understanding of how it works. 
Now I think I can make some better scripted tiles and I have already developed fully functional 48 tile blob tiles for my usage.
good news.you may look at TileTool2D’s script in AssetStore