I do a lot of free-standing "holders" from industrial (5 ply) cardboard and hot glue. Surprisingly sturdy! Made a video about this too: https://youtu.be/s-aNW3h15K0 - all of these are still in use and I made more & more complex ones too.

Seems the calculator is designed for a "collection of boxes", which I guess is a start, but when I hear "organizer" a collection of separate boxes ain't what I want. The most significant factor of making one's own is that it's 105% customized to the need, no more no less. That means usually a lot of thought between "target place bounding box" vs "bounding boxes of things the holder shall hold".

For "organize a drawer, quickly!" I got myself a couple of sets of "modular" boxes - they have little tabs on their sides so one can snap them together like lego.