This is such an excellent observation (about Graphviz); you can see some of the rough outlines of the primitives that might get the job done, and how they might

This is such an excellent observation (about Graphviz); you can see some of the rough outlines of the primitives that might get the job done, and how they might be composed. This area is so ready for new work. There are also some problems that maybe don't arise the same way in stat graphics and charts for data journalism, like coping with nested layouts, stable dynamic layout, optimizing topological properties, and intricate combinatorial optimization problems, to name a few things.