This reminds me of the old (amiga) populus and powermonger games … wait didn’t I mention this before?? 
An old idea came up while watching the video, … waterfall … maybe some other has posted a similar idea but I did not find anything usefull …
Waterstone and Blackstone.
A Waterstone creates water and a Blackstone destroys water as fast as the Waterstone creates it.
There are natural stones in the world which the game would use to create waterfalls or rivers which flow out of the map and the “alchimst”(herbalist tier 2) could be able to create those stones, which need a looooooooooooot of resources.
Which would crafting those stones feel like you have crafted something important and not like another chair etc…