Caravan and Freight establish food, production or trade connection

Every Caravan and Freight can establish trade routes, but only trade at the moment.

Do you like if this type of units can establish choosable food, production or trade connection? So that, you can boost the food, the production or the trade points of your and the target city? It can help you at the expansion phase by "instant" food, production and trade points and it can help you build the space ship via production points.