I think it woud be great if we have the possibility of chage the shape of the principal nodes in the graph-view. When you already used all the different colors you coud in your notes organization, then don´t make sense to keep doing it. Your graph-view its difficult to read and to find a specific relations of nodes from the long distance in your graph-view. So, why not add the possibility of change not only the colors of the nodes, so the shape of them? Or even insert icons like ones!
Tell me what do you think about it. Is it viable?