Cerebral Palsy can be problematic
My nephew with CP makes spasmodic movements with his arms and legs and can't be in a cockpit with controls within reach.
As long as the passenger can keep limbs away from the controls, or they can be disconnected if not, there's not much problem.
At our glider club, we regularly give rides to disabled people and have a hoist and sling to get them in and out of the glider. Many of them enjoy having a go on the controls after release from the towplane.