Not exactly. I’ll explain in a moment, but first, what I was referring to and what DFS was referring to are two different things. Without a copy of DFS in front of me to look at, it seems DFS is defining literary terms that describe the relationship between audience and character in the story-mainly, what information the audience does or doesn’t have vs what the characters in the story do or do not have. The reference I made was to the idea of the IC throughline as one possible perspective that a single mind can take. As a perspective, it’s not about what the MC or Storymind or audience know, but about how things are being observed-or perhaps I should say where they are being observed from.
An example. Character A has a task to do but doesn’t know how to get started. Character B also has a task to do but seems to know how to get started. Character A wants to know what Character B does to get started. Assuming Character A is an MC, as soon as they look to Character B to see how to handle the problem, Character B becomes the IC to A’s MC. A could look over her shoulder at B to see what B does while not having a clue what B is actually doing. Or A could ask B and B could tell A everything. Either way is still an example of A wondering what B is up to. So again, it’s not really whether the MC or the audience know what’s going on in the ICs mind or whether there’s any actual hidden info from one character or another, or even whether the audience knows what’s going on that creates an IC. What creates an IC is when the attempts to solve a problem by one character or perspective are influenced by the attempts of another character or perspective to solve a problem.
So to answer your question, deep POV scenes with the IC are allowed. They just need to influence the way MC perspective of the Storymind is attempting to solve its problem.