Nice visualization! I wish there was a way to share the graphs. An interesting thing to notice is how the previous (hard to find) optimal solution is lost when

Nice visualization! I wish there was a way to share the graphs. An interesting thing to notice is how the previous (hard to find) optimal solution is lost when adding a node at the opposite side of the graph (which is far enough to be irrelevant in most cases). I would therefore just insert the new point between the two closest nodes, and keep the same path as the starting point for the optimization. Of course, the risk with that methodology is to fall into a hard-to-escape local maxima. There is probably a way to infer how much a new point will affect every given node, so maybe a better way to proceed would be to identify those that are likely to be affected, and only re-run the optimization from scratch for those. Of course, where you position the limit itself is an optimization problem... (edit: or just persist pheromones, regardless of the new points?)