So when a Feruchemist or Ferring stores an attribute they lose some of that attribute while actively storing e.g. losing sight while filling a tinmind or losing strength when filling a pewtermind. What happens when they store investiture in a nicrosilmind. Would they not lose some of the ability to store attributes and burn metals, if they are twinborn? Does this mean that there are differing levels of power for metalborn, are some more powerful than others (not as much of a difference as a lersium mistborn compared to a regular one but still)?
Basically when filling a nicrosilmind does the metalborn lose some of their power for a bit and can they tap it later to get a surge of power a bit like duralumin but without the metals or stored power being used up instantly?