It's not just big interlocking drawers, or small drawers, but both. The drawers and joints are designed so that four of the small drawers take up the same space as one big drawer.
They're pretty easy to print, and the drawers should fit into the modules as is, without resizing anything.
I'm thinking about adding options for the drawers, like dividers and such. If you have ideas or requests, let me know in the comments.