MASH is a really great tool. It's not super useful for character rigging, but I've used it several times for props, specifically conveyor belts.
The simple way to set up a conveyor belt is to to create a single "tile" of the geometry. Use a MASH distribute node to turn it into a line of those segments. Then use a curveWarp deformer with a closed curve in the shape of your conveyor belt. To animate it you can connect into the curveWarp deformers offset attribute.
There is one major limitation. The curveWarp deformer will match each vertexes position in the bounding box to the corresponding point on the curve. So a point in the middle of the bounding box will be attached to the middle of the curve. What this means is that the mesh cannot overlap with itself on the curve. That can be a problem if your segment interlock like these types of pieces.
There is a workaround though: