high level theoretical physics? Are you refering to ideas like wether this is a "deterministic universe" (where free will is impossible and each choice is already predetermined by a previous event.) and the theory that each of our choices could lead to a "multiverse" where each possible choice and variable is true?
A lot of that is nearly impossible to test wether it's true or not and will remain theoretical for a long time.
Exploring the brain and how it works (with free will) via science doesnt sound like "pseudocience" to me but eh and at least it sounds like a more practical way to attest the truth.
At the end of the day it's possible both neuroscience and physics end up contributing to the solution.
