I designed this with specific use cases in mind for my own organisation, but it's quite versatile so I hope it can be of use to some other people too. Below is what I imagined for my use case for each compartment.
This is quite a large build, making use of the whole (depth) of the build plate of the i3 mk3s+. I've included a rough guide to what the internal dimensions of each compartment below to help give you an idea. Clockwise, from back left (large compartment):
Full print size: 210x210x100mm
Print settings: 0.3mm (Draft), Lightning infill (10%), No brim. Print time: 13 hours (stealth mode)
Having printed it, everything fits more or less as I imagined, but think a few adjustments could improve things, so I'll upload any updates as I make them.
The author marked this model as their own original creation.