Hello there!
My last two world were terrible because of the lack of salt. I spent too much time at the mines trying to find Halite, and it's become very annoying. Salt gives you a lot of mechanics, and i wasnt even able to give it a try.
Therefore, i have a sugestion. Last week i was at real salt mine caled Wieliczka, Poland. There was museum part which told about realy old techniques how people gather salt from salty underground streams. They did this by boiling salty water to gather crystals. Would it be posible to add something like this? Gathering water from the sea / salty stream that comes from underground, and evaporating salt from water? Thanks!