So, I have some thoughts.
Nicrosil metalminds allow you to tap genetic investiture for a smaller amount of x metal investiture. Being a Nicrosil Compounder you can eventually become the Lord Ruler, in its own right. So, what if it also can be tapped for the investiture of other magic systems, like how Wax could burn all of the metals with Allomancy, it would explain why the charges depleted at the rate they did.
Also, I assume that Lerasium acts as something very similar when used with Feruchemy. It might even generate it's very own generic investiture.
So, for instance, you could tap that investiture to be able to use any metalminds, or burn any metal, or access the For, or use Breath.
It could explain why Hoid revers his Lerasium as much as he does. Allowing him potential access to the magic systems in other planets. One of the, so called, "hacks" for each magical system.