This can be attained in Assisted Mode, made easiest with Claire who can bruteforce her way through a bulk of the game's content. Go for the safe on 2F of the station first to get the side-pack, and go out of your way to get as many of them throughout your playthrough. Use up all keys so they can be discarded, same for the network scanner you get in the NEST labs. Even with max-size weapons, a fully upgraded Claire can still have several slots free.