Has anyone put any thought towards making domain management more complex? One of my players just mentioned that he'd just sort of assumed there were rules for Dwarf Fortress/Banished style "Oh! I'll build a blacksmith so my community can have metal picks! Then they can mine enough coal to not die in winter! When spring comes, I'll put in a saltworks." and was surprised to learn that the full extent of domain management was fortifications and abstract "investment"
most of the micromanagement is in troop composition, marching armies, and sieges.
You have a little bit of managing with potentiall unruly vassals, granting them favors and whatnot, as well as the ability to decide how much to tax, how much of a garrison to keep, and whether or not to have festivals.
The other stuff though is better modeled with a Patrician IV outlook than Banished/DF, and it would be in the mercantile ventures rather than domain management.
For example, say you hire a swath of blacksmiths and construct them a nice smithy. The underlying rules imply you'll make roughly 3% per month on your investment, meaning you'll recoup in about 3 years. Suppose you wanted to do better than that: you could attempt to purchase enough raw materials at a lower cost, say common metals for a blacksmith. It's assumed some % of a blacksmith's time is spent bartering their work in exchange for materials they purchase at cost. Construction projects tell us roughly how much labor can be speeded up when the materials are already provided, which will create a larger total amount of goods produced than the 160gp worth than the usual 1 master 2 journeyment 4 apprentices. The difference between 160gp and the higher amount, less what you spent on the raw materials, is your extra profit. If you want to get fancier still, you could collect your arms and armor and ship them to somewhere where demand is high to try and get yet a better return on investment.
If I recall correctly, there's a hint of that level of detail in the Sine Nomine domain rules ("An Echo Resounding"), but it's actually mechanically more abstract - you just have to come up with some narrative justification for the +1 or -1.