Not sure exactly how his setup is, but it looks like he's just added two filled polygons to a sheet that is on top of everything else, and then added text and decorative symbols on top of that again. Probably 3 or 4 custom sheets. (background, text, symbols, border)

And last new atlas map for today. Thanks for the contribution.

And here it is in the atlas:

Now in the atlas. Thanks for the contribution

Finally got around to get these into the atlas. Still not the end of my backlog, but at least a solid chunk. Thanks for the contribution.