First time posting here so I'm sorry if I haven't covered any spoilers properly. I've read the spoiler guide and I think my post title is okay, apologies if not.

So I've just finished Oathbringer and I had a few questions about bondsmiths, so when Dalinar opens the perpendicularity and becomes an investure conduit - I'm assuming it was just pure investure not just stormlight, I'm assuming theres some kind of distinction - Stormfather says it's never happened before, does this mean there has never been a 3rd ideal Bondsmith before? Or just with Stormfather specifically do you think?

Also metal minds are are keyed to a specific person and attribute, they can be open but it's the attribute I'm fussed about. With a gold metal mind - Love you Wayne - do you think Dalinar could in theory fill it with investure and then it become full?