You are correct that my comments are missing the mark. Still, there is a sense in which the kinds of non-determinism represented by Born probabilities present problems for Si.

They would represent problems for determinism - if they were "real" probabailities. However the idea around here is that probabilities are in the mind.

Here is E T Jaynes on the topic:

It is a commonly heard statement that probabilities calculated within a pure state have a different character than the probabilities with which different pure states appear in a mixture, or density matrix. As Pauli put it, the former represents "Eine prinzipielle Unbestimmtheit, nicht nur Unbekanntheit" *. But this viewpoint leads to so many paradoxes and mysteries that we explore the consequences of the unified view, that all probability signifies only incomplete human information.

[*] Translation: "A fundamental uncertainty, not only obscurity"