I see that the connection layer has to be in front of the mainLayer, or the demos don't work. As I understand it this is required for the order of calculations.

For my design, I want the connection lines to be behind the boxes, and I will make the boxes semi-transparent, so you can see the lines in a subtle way if 
they cross behind a box.

Can you please add a feature that would allow the drawing order to be independent of the layout calculation order?

Thanks