Just coming across this post now. I see you’ve done a lot of research already and it’s impressive! For this case, have you looked into Multiple Sclerosis and Parkinson’s Help?
These fields are made particularly with this case in mind. Also, enhanced visual processing helps a lot with motor movement but it might be strong in the beginning. Accessing the potential will be made easier with the neuro-focused fields and gaining ability over them will be enhanced with visual processing.