So then why not just make it so a diagnosis of autism confirmed for that candidate counterbalances the test? Also, because of the manipulative nature of NMP, usually you don't give someone you suspect of having it the trst for them to fill out. A professional would observe them and fill it out.

Where to get the testers from? Draw them at random from the qualified ones in general practice during each election year. Can't be worse than our "every dumb Tom and Harry votes" system - at least these people are likely a bit smarter.