This UI I find is very clunky and hard to learn, the UI doesnt feel very intuitive, i see many posts about people struggling to get this to work because of that.
I think it would be good if they made this more clear, by setting up a IU that makes it clearer what is going where. Like a graphical representation of the settlements, with to and from arrows, then you can click on the arrow to add or remove goods, so its deadly clear what you are setting up. Or if the Arrows arent clear, select the From "outpost" and To "outpost".
My drawing is a concept but it describes what I am suggesting, an easier way to set up and manage deliveries. You could even reuse most of the current UI, because of the way it works, but make it more intuitive by using graphical representations to filter the list a different way.