First welcome to the Forum. I hope you stick around, and become part of the community.
Second. Dwarf Fortress Geology is already pretty realistic. And you can change the mineral abundance when you start a new world.
The smelting practices for the metals in game are pretty similar to how their done in real life.
Thanks! I'm still pretty bad at this game, but even following it's development has been really awesome.
Yes, the smelting practises are pretty realistic, especially the material requirements fordifferent alloys. I had mainly in mind different sort of smelters. Copper could be smelted in basic furnaces or maybe even just kilns, whereas iron would require bigger bloomery. Pig iron and steel would require big blast furnaces with big bellows, that would require power. This would also make power sources like waterwheels more important.
More abudant iron would make it easier to find a nice place for fortress, but adding some more challenge to it would keep copper and bronze as important materials for tools at least at the pioneering stage. Copper alloys would be mainly used in currency(after its added) and crafts(as the case already is, I reckon). If DF had tools like shovels and hoes they'd be even more important (copper and bronze were somewhat commonly used in agriculture still in the medieval period, if I recall correctly). Adding some necessary junk like plows and hoes to make farming possible would be a one way to make it a bit more challenging, although maybe not much. But yeah... I'm just thinking aloud and off-topicing right now, not really suggesting anything that has been thought through. Sorry
I'm also a Finn, ergo possible spelling/syntax errors and use of words like ergo, when I'm struggling to find right words.