Just so you know, the theory is not based on any evidence, I just came up with it.
Ok, so ferrings can't tap into other ferrings metalminds right? So what if while they're storing their identity in aluminum, they can tap into other metalminds? It kind of makes sense...
Also, on a side note, does anyone else feel like ruin shouldn't be able to change info in metalminds? Because the information is kind of set in metal. And why can't allomancers effect aluminum, it sort of make it seems m like allomancy is magnetic... I except gold isn't very magnetic either... I don't know...