Wouldn't you know it, I've been messing with the current release candidate for FreeCAD lately. Just now, I used it to make this.
I got annoyed at having to search through all these multipacks of files to find a Gridfinity bin in the size I want. So I decided the hell with it, and made a parametric configurable FreeCAD model that creates bins or you, in any size (within reason) and also with a configurable number of fixed dividers in the bargain.
My main intent was, of course, to use these to organize oodles and oodles of pocketknives. You'll never be able to guess why. But if you have a use for it, knock yourself out.
https://www.printables.com/model/274917-gridfinity-rebuilt-in-openscad
Bookmarked, thank you!