I threw together some super rough python code with a single child controller and started testing the mechanism driven by the hobby servos I planned on using in the end.
This prototype uses the sheath implementation. (Far right listed below) Which replaces the first disc prototype. The key difference is that the cube no longer touches the shaft at all and rides on the sheath. The discs relied on friction to hold their position and were difficult to get consistent spacing on. This caused the pixel to not sit square to one another, instead, they were displaced in the vertical dimension from one another.
Link To First Prototype
This first prototype ran well most of the time. However, the pixels would bump horizontally adjacent ones. This seems fine, but would cause failures in the accuracy of the final display.