The sizes this follows
One grid unit is 42 mm by 42 mm. One height unit is 7 mm, measured from the bottom of the foot, and the first unit includes the base. A 2×3×4 bin without a lip is 83.5 × 125.5 × 28 mm. The half millimetre comes off the whole footprint once, not once per cell, so neighboring bins keep a small gap.
Each cell gets its own foot: 0.8 mm of chamfer, 1.8 mm straight, then 2.15 mm of chamfer, 4.75 mm in all. Magnet pockets are 6.5 mm across and 2.4 mm deep, four of them, centered 13 mm from the middle of the cell. Screw holes, when Pro is on, are 3.2 mm and stop short of the floor. Dividers are 1.2 mm and stop below the lip so a stacked bin still has room for its feet.
The generator uses manifold-3d, a WASM solid kernel. After the booleans it welds vertices and checks that every edge is shared by two triangles. A sealed result is what you want before a slicer sees the file. It is still worth dropping the STL into your slicer once, because a browser mesh is not a substitute for a test fit.