No need for an apology. I am happy you are learning CabWriter and am here to help any way I can.
Overlay doors/drawers, at the moment, work a little differently. When CabWriter was originally architected and written it ignored overlay doors on the assumption that most custom cabinetmakers didn’t use them. Over time we had enough people ask for them that I added them, but in a way that caused the minimum re-write at the time. Essentially what happens is that the user selects door/drawer sizes as they had originally; i.e. in the Face Frame tab with the red/green lights, but as thought it were a face frame design with all stiles and rails drawn, and inset drawers. Then CabWiter takes that drawer height, adds two gap and two overlay defaults and draws the door/drawer to that dimension, botu overlayed on the face frame.
As an example, see the attached images of an overlay door/drawer set-up. Notice all stiles and rails are drawn. Though you can’t see it on the Face Frame tab, Overlay is selected on the project tab. In this set-up I used 3/32″ gaps and 3/8″ overlay. The 5 5/16″ top drawers will be drawn 6 1/4″ high; (2 x 3/32″) + (2 x 3/8″) + 5 5/16″ = 6 1/4″.
In the next beta release we are reconfiguring how a user selects a cabinet style and Overlay will be an equal partner with Face Frame (inset) and Frameless. In fact the choices will be Face Frame / Hybrid, Frameless / Hybrid or Overlay. See new_dropdown.jpg. I will take a look at how much code change is needed to adjust the Drawer Height calculator and may change it to accept final overlay dimensions. I know I owe you a video on how to use this calculator, but may wait to see if I make this change so I can include overlay changes.