FWIW, I use the free version of Onshape CAD software to design tab and slot boxes and frames. Someone designed a macro (called Featurescript in the Onshape community that lets you automatically insert the tabs and slots and automatically size each. I use a variable dimension for the material thickness to adjust the slot/tab dimensions so that the parts fit together. It can take a little trial and error to get the values adjusted just so but that’s easily done with small test parts.
Here’s the entry for the Laser Joint Featurescript:
Hopefully that is visible to those without an account. I tried to upload the PDF that describes the feature in detail but the forum software doesn’t allow PDF uploads apparently.