Brandon seems to have answered this in 2015 and 2018 with a RAFO
this doesn't seem accurate to me. If it only stores your ability to use investiture, then it doesn't make sense for a Nicrosil metalmind be able to form a perpendicularity (piercing the Realms), which Brandon confirmed it could. It seems to me that you're thinking of Hemalurgic Nicrosil. I would love to hear any evidence you have for your claim that I might have missed though.
edit:
I found this WOB a little later that is the closest thing I saw to supporting your position, but I think it's pretty unclear exactly what F-Nicrosil does.
it seems to say that they could store the abilities, but other WOBs seem to say you can store the Investiture itself, so it seems ambiguous to me.
Immortal Platypus's post in Can you store Stormlight in a nicrosil metalmind? was marked as the answer