I don't know if this has been done or if it is possible. I would like to request a mod that changes the trading mechanics a little bit. When a trade route passes through a trading post created by its own civilization, can the city that contains the trading post earn something like a gold. This way, when you are creating your early empire, it can add a layer of strategy about putting cities in places where you think many trade routes would pass through. Another strategy in the middle game would be to look for islands between landmasses when the landmasses are more than 30 hexes away. Then that city would become very valuable because many trade posts would be created in it.