As you probably know, Feruchemical Nicrosil can be used to store Investiture. However, like other Feruchemical attributes, it doesn't make sense to store a fraction of Investiture. Lets use Allomantic Steel as an example. If The Lord Ruler (using him as he has full access to both power sets) were to store 50% of his Allomantic Steel power in a Nicrosilmind, would his steel pushes be half as powerful as he is filling the Mind?
Alternatively, perhaps Nicrosilminds are filled all or nothing. Maybe, the TLR fills the Nicrosilmind instantly, and when he stops, he is completely devoid of the ability to burn steel Allomantically. Then, someone else could come tap that same Nicrosilmind (assuming it had no Identity) and immediately gain full access to Allomantic Steel forever, even when they were to take the Mind off. In this scenario, Nicrosilminds would work like a gift, giving an ability to someone, until they can give it back.
Does anyone know how it works, I would like to know, just so it will be easier to comprehend things in The Lost Metal, which I assume will be full of complicated Identity and Investiture storing. So confusing, please explain?