Expose primitive points in the scene hierarchy

This is almost certainly oversimplifying things, but I wonder if it would be possible to expose the control points of primitives (mostly tubes) in the hierarchy as children of their parent. Then if other objects could be added as children of those control points, they could be moved along with the control points.

This would allow for nondestructive modeling and modification of things like tube ends, hands at the ends of tube arms, etc.,