Seeing as if 4D

[anagogy]

The spirit does not reside in the complexities of the brain. All beings have all possible rays in potentiation.

While I agree with you that the spirit is not limited by the brain, the "mind" is, in fact, still limited by the brain. I like to think of the "spirit" as the relationship between the mind and the body. Or the "integrator" between the subject/object nexus. One can be a sixth density wanderer in spirit, but if you are in a 3rd density body, you are more or less limited to 3rd density patterns of thought. You will still have an "armor of light" as Ra calls it (a bias towards the truth apparent in higher densities), but you will still remain completely the creature of 3rd density.