OK. Who pays for it?
I don’t see standing in his way, but I would insist on a reliable means for him to communicate once he becomes fully dependent on cybernetics to survive. I would want him to be capable of clearly expressing the quality of life he is experiencing. If he is in pain, real or imaginary, or worse, I would want him to be able to let people know and take appropriate action.
Stephen Hawking had the advantage of a superior intellect that permitted him to find satisfaction in mental activities that the average person might find totally unfulfilling.
I have seen this movie
https://www.youtube.com/watch?v=mISUM0qvFTQ