Actually it has three heads. You can see my little LED Testdongle on the third port. It just lacks an additional SSR and an extruder, which I did not want to add until the rest is working. The adapter also prevents marlin from failing as it simulates the temperature probes from the third tool head. The wire loops are the Sub-D cables for the tool head I needed to store. Since it is an extender cable cutting to size would be a massive amount of work.
The rest is color coded and pretty easy to maintain. I even spared a lot of wires as I only have one end stop on the entire printer and all Nemas are on the back side. Also there is not a single wire in front of the electronics mount beside the display wire (which is loose as I need it mobile to work behind the printer) and the one end stop wire.
I have a lot of experience with soldering and cable making, so I would have just rigged up some DB9 solder connectors cut to length. But, not everyone has a good soldering iron, or the experience. It is still an impressive piece of work, and I admire your planning ahead for the possibility/inevitability of an enclosure.
I did use DB9 solder connectors on the tool head side. The extender cables where just in storage and I was to lazy to create my own wires. I probably will do later, as for example the heater power lines should be a little bigger in diameter. Currently I am more on to finish the basic mechanics and software to get it to work. Such details can be done later on.
One problem I still have is to prevent the ptfe tubing + wiring from being so floppy. The cables from both tools can easily rub on each other and get in their ways.
Also there is not a single wire in front of the electronics mount beside the display wire (which is loose as I need it mobile to work behind the printer) and the one end stop wire.