Parametric Rounded Corner Box with Optional Lid

I often need a custom enclosure for electronics projects, and the rounded-corner style I like is very difficult to create in Tinkercad. I found a few box generators here on Thingiverse, but nothing seemed to be complete. So, I decided to learn how to use Open SCAD to create a parametric generator for a customizable rounded corner enclosure with an optional companion lid. The result can be exported from OSCAD as an OBJ or STL, suitable for further modification and/or 3D printing.

To use the generator, load the provided .SCAD file into OSCAD and press F5 - a box with a companion lid should appear in the preview window. The dimensions and other parameters are set with the line

rounded_box(54,41,25,2,3,true,2,2,1);

at the bottom of the file. This generates a 54x41x25mm hollow box with 2mm radius corners, 3mm thick walls, a 1x1mm ledge for the companion lid, and the lid itself. Change these parameters to suit your project and regenerate with F5. When satisfied, use F6 to re