I’ve provided a lot of different of the balls. Last one was for someone in bed and needed to control the whole pc with his chin. We adapted the base to fit on a mount. Other uses for people with ALS with reduced hand function - altered the ball shape to hold the hand.

Yes. Then I couldn't come up with a case where the trackpoint would work great but not a trackball.

Probably my lack of imagination, the article is about desk setup, and while you can move a trackball with basically anything that has friction, a trackpoint is a lot smaller and finicky. A joystick could be a better version if we're thinking adaptive input.