This is my another project, similar to the other one I did:
https://www.thingiverse.com/thing:5339928

...but this time to print everything separately - the base and the pockets at the size you really need them.

This one is more practical in my opinion due to the rounded edges and being allowed to actually take pockets out of the base if needed. It can also be customised for your needs with different sizes pockets to suit everyone.

It is on a big side though:
Overall size is 250mm x 250mm
External walls of the base are 1.8mm thick
External walls of the boxes (all sizes) are 1.2mm thick.

I also recommend to print the boxes with the option "filling gaps between walls" (Cura) disabled (if printed with 0.6mm nozzle at 0.6mm line width)

Update:
I have just added to more sizes:

• box double widened
• box triple widened
  (both compatible with the rest of boxes)

Artillery Sidewinder X2

No

Doesn't Matter

0.48mm

30% for base (lines)

I would recommend using brim to hold it down to the bed better unless you know your filament and sure that there will be no warping.