1) Ways to spend coal. A lot of people have stockpiles of stocpiles of it. Myself have 30 stockpiles of lowq coal, other people have 50, 70 stockpiles. Everyone can run 20-30 tarkilns and no one know way to spend a lot of it. So... Maybe then we will be able to make curiosity from them? Something like graphite? Idk, really. But we have too much of it and no way to spent it in this amounts.
2)Sand. It's very difficult to find really highq quality sand. And since there is way to craft highq clay, maybe there will be a way to craft highq sand? Smashing stone or cat gold on anvil maybe?
3)Snow. Same problem as with snow. Freezing water in barrels in cellars of snow mountains? Mixing water with snow to get new snow? Any other ideas?