Currency exchange buildings are the natural way for a shop to smoothly transition from using personal credit to using a local or global currency. I finally built one as a homesteader but discovered too late that it's considered a civic building and won't work outside of a settlement at all! Why does it have to be part of a settlement? I have an account with my personal credit, and with local currency - I should be able to let people exchange them (one-way) to exchange their holdings of my personal credit for local currency.