The ability to craft/find (or be given a radio by a trader upon first meeting them) could be used to accept and finish quests with traders, naturally you wouldn't be able to receive the rewards due to not being near them, and having the items randomly appear in your inventory would be immersion-breaking, to counter this i propose a box appears by the trader that gets filled up with the rewards of quests, allowing you to simply arrive and pick up the loot the next time you visit the trader after telling him what reward you would like.