Allow outpost resources on cargo dock with contract

It seems like the game doesn't allow the player to setup a cargo dock for a contract using 2 modules, and then use the remaining modules for "normal" outpost resources. This makes large cargo docks awkward and less useful than smaller cargo docks because they take up more space, but only in exceptional circumstances can be fully utilized for a single contract.
It should be possible to setup 2 modules for the contract assigned to a cargo dock and then set the remaining modules for importing from outposts like any other dock. When the ship departs for the contract, it'll pick up the assigned outpost resources as well, if any exist for pickup.