The IP elements: Questions concerning differences in internal focus between Si and Ni

[Skepsis]

Ni is like having Si with an additional layer, which makes Si operate beneath the surface. Si is there, but diminished, making one's primary focus on the world abstract and imaginary. An interest in the abstract to an extent that it takes siginificant time away from more practical pursuits, indicates more of an N preference. The fact that you are here is more indicative of N than S, imo.

[Chakram]

Ni is like having Si with an additional layer, which makes Si operate beneath the surface.

This makes no sense. You could say that any IE is like having other IEs that operate beneath the surface, because that is what happens for every type.