https://hackaday.com/2021/06/27/mechanical-7-segment-display-uses-a-single-motor/ https://hackaday.com/2021/06/27/mechanical-7-segment-display... This is the a

https://hackaday.com/2021/06/27/mechanical-7-segment-display-uses-a-single-motor/ https://hackaday.com/2021/06/27/mechanical-7-segment-display... This is the approach I would take to this problem. It could be miniaturized a great deal. Notched cams seem like an obvious win here.