Sloped variants of the built in walls to fill those holes.
As you may have noticed, I'm not great at the HTML side of things, so I don't have much in the way of pictures, or a description of the mod.
However, 'Random Gamer' on YouTube who is making Satisfactory mod highlight videos, has kindly made one for this mod.
If you want to see the mod in action, you can find it here in their YouTube channel: https://www.youtube.com/watch?v=Yc_x3B-ARdk
They have other mod highlight videos, so be sure to check those out also!