To be honest, I was thinking more along the lines of providing a solution by changing the way players have to manage stuff. And also, to manage trade.
Right now, there is literally no reason to enter into trade with anyone else. Similarly, you have a huge excess production problem going on right now in your fort. Even if minerals scarcity was to be enforced, there is still little reason to trade with anyone else apart from the dwarves. The humans offer of two or 3 metal bars and leather is quite useless when compared to mandates.
We don't know how well the issue of supply/demand will change gameplay, but frankly, there is no "need" to engage in trade, so supply and demand won't be game changing. Your dwarves will still have excessive production. I have literally no problems in running the whole gamut of trade industries, from mason products, crafts, glass, leather, cloth.... the only problems I ever have is metal and that's due to my reluctance to bring up magma 70 z levels to the surface.
So. Let's "fix" that. You have excess production? Ok. You now have a need to actually "dump" that production by selling, because you need to meet wages or face a tantrum spiral.
Sieges can no longer be turtled off, because while you can meet all your physical needs in house, unless you have planned for it beforehand, you're going to run out of the currency to meet your dwarves wages in time.
Once you activated the economy, you're going to have to meet this challenge of minting wages, and that's ignoring how outposts, armies, or demands from the mountain home may link up with this.
If you want to be entirely self sufficient,you're going to have some means of minting your own currency which will bring about its own challenges, especially if you bring supply/demand, inflation and deflation into play there... I have some ideas along those lines, but that will depend on how the new markets and etc are going to come about.
Imagine how if rents on bedrooms go up and down based on keynesian economics. If you have excess cash floating around that could be spent, then rent go up as there's too much money in the system chasing the same amount of goods. Too little and you have reduced demand, so, rent go down to chase the number of people who can buy the services. Ultimately, don't have enough cash and you get scenarios like deflation, or just your internal economy shutting down.
This ignores the potential for tantrum spiral or the equivalent of work stoppages/strikes. We do know representation to guilds/mayor is going to come back. No money to buy goods= nobody buying food and drink= your fort shutting down as your population starve..... which leads to you not being able to produce anything to sell or mint your cash or etc and bring it back on an even keel.... before the starving masses rise up in riot against your rule and anarchy/communism resumes:D
Of course, hermit forts could still be settled because you could simply not activate the economy by not meeting the conditions or by balancing self sufficiency in terms of wages and cashflow, minting is the idea I have in mind, although it may require some other stuff if mineral scarcity is also enforced. Taxation, internal economy on markets and dwarven shops selling government goods to your citizens.......