Given that in the update will allow for refueling via cargo, it makes sense that cargo should be able to hold other limited slot items. It should take some time to unpack the items so that you can't do it effectively during combat. But this would make it possible to "restock" limited supplies without heading back to base. Or to have real supply lines with cargo based ships providing munitions and sundries for friends/allies operating at the edge of civilization. This might be particularly useful if/when we ever uncover a Thargoid presence outside of human space.