Hanging Wire Spool Rack

I love the Adafruit hook-up wire spool set ( https://www.adafruit.com/products/1311 ), but the cardboard box it comes in takes up too much of my limited workbench space.
I've thrown together this hanging spool holder and it's completely solved the problem for my particular situation.

Note that I'm using a cheap workbench I bought from Bunnings Australia:
https://www.bunnings.com.au/pinnacle-compact-garage-workbench_p2760256
This is designed to fit that, but I've included my original FreeCAD file if you want to make changes.