It is a very interesting question. Though perhaps more complicated than first assumed. I dont know if it would prove that hyperspace is not manifested in our mind during CEV experiences. Assuming that the eyeball and optic sensors are completely non functioning from birth, it is still reported that people with congenital blindness can dream some elements of visual content.
The parts of the brain believed to be responsible for dreaming should still be functioning despite whatever sensory organs have failed. Though a person born blind may visualise a tree in a different way to a sighted person, it is rather difficult to prove that.
It could be fair to assume that the parts of the brain engaged by tryptamines would still function as well. The content of the visual experiences would be up for endless debate of course. Though realistically, a discussion between two sighted people about hyperspace leaves us just as confused and uncertain in many cases.
I would love to hear a report from a blind person who has taken DMT
I don't know much, but I do know this. With a golden heart comes a rebel fist.