It’s interesting how quartz composer solved the wiring issue when wires cross a panel. Wires are always in the back and the panels are actually slightly transparent so you can see wires crossing panels in the background. As said wiring is not the main goal here but could be done with scene transition commands and custom behavior calls.
As seen in this screenshot panels are free form and arranging them is up to the user. That would be different in the “Trello board” like overview.