I have seen layouts with more than 13 layers. There is not a limit to the number of layers that the tool can handle. Anyway, please report here if you find some issues increasing the number of layers.
The only problem that you may face is in the fact that the color assigned to the layer are maybe 10. Therefore there will be different layers with the same color.
This reply was modified 3 years, 10 months ago by Umberto.