[Kazeto]

Hmm ... I'll say I like the idea. It would require reworking how the market works but generally repeatable trading quests—in spite of delivery quests generally being monotonous—would probably be less bothersome to people because it would keep them doing something different.

That being said, if such an option were to be implemented I propose adding a module that would increase cargo capacity even more than a normal module but at the cost of only being usable for those missions; you needn't even be creative with the name because calling it “Shipping Container” or “Delivery Module” would probably work.