First of all, thank you to @MarcElbichon for the nice design.

As you wrote: "If someone have time to export to individual stl, don't hesitate ! ;)"

Separated with Autodesk Meshmixer, here you can find the objects in single files for the 1U drawer.

Naming of the files is depth_x_width.stl, but see the attached image.

1x.zip = first row
2x.zip = second row
...

ALL_1x1-12x12.zip = all in one file

Modular_Drawer_Base_1U.stl = Base part to put in the single drawers