I think it would be neat if, at arsenal stations, you could lend your gear to another player in your party.
Say you're at a fiend level and you have both a dread skelly and a crest of almire, and your buddy only has an Owlite or BTS or something. You could equip the dread skelly yourself, and then lend your buddy the CoA, which would give him the ability to equip it until the next arsenal station, while blocking you from equipping it yourself until said next arsenal station.
If you leave the party the equipment would stay equipped on the person borrowing it. If you start or join a different party you'd be able to equip it yourself (so that people who borrow your stuff can't just camp on your gear forever), but if you tried to rejoin the same party with the lent gear equipped, you'd be prompted by the game to change your gear before it allowed you to continue playing. (like, it'd keep you in the invulnerable "I'm still loading the level" state while you choose some other gear)
This just goes against a person having their own gear to begin with.