It looks very simple, it indeed become very simple, once you understand the logic what to do and how to do it.

That is how you do it.

1. Render setup (My Render Settings 01) - activate Render Visible Edges

2. Setup Symbology for Visible Edges - by clicking Magnifying Glass and set in Symbology Tab "Visible Edge Override"

Here is important the line style and line width. Choose "Solid Line (0)" as default for line style and "Thick Width (2)" as line width.

Note that Colour of the line you will be able to change later, but the thickness not.

3. Run your render with Modified Render Settings (My Render Settings 01)

4. Once the render is complete the Button "Overlay Visible Edges" will be activated. By pressing that button you will activate display the visible edges in your render.

Here you may change the colour of the visible edges lines.

Good luck.

Nikolay