I think I'll put an extra cap on immigration of some percentage of the settlement population so it doesn't balloon up in size too quickly.
Even dwarves need some comfort and will only sleep on wooden beds! Metal pillars are an option although I'm moving away from metallic furniture unless it's going to be built out of pre-crafted components. Just hammering a bunch of ingots into a piece of furniture doesn't feel right. The next content update will include metal plates as an intermediate product required to build some kinds of metal furniture.