I am not familiar with "internals" of the map.
The grid is 3D? I guess? And dds files are textures, that span over given squares. So these are different types of files.
The change, you mean to 3D grid?
Nah, by grid I mean the 2D visible grid that appears around plots when you click "ctrl+t". I reduced the resolution of the texture containing the grid by half which led to twice a thick grid width. I also decided to make the grid black as the thicker grid was quite blinding/glaring when white.
P.S. I looked over the textures in this pack; and found the style interesting.
-Rocky had too much perceptual depth (for a 2D texture on a flat surface without normal mapping) but was overall nice.
-No complaints on scrub; it might be the most elegant looking terrain of the pack.
-Plains, Muddy and Marsh looked like satellite pictures covering a large area which did not match the other terrains who looked like they were closer and covered a smaller area. It made them too varied and a bit out of place.
-Ice had very little variations which made it look too blue, A little white snow covering here and there would probably look good.
-Permafrost was far too bright white but I liked the overall style of it.
-Barren had too much craters and it looked more like lunar terrain; a nice terrain but quite out of place.
-Lush and grass were imo too similar.
I will make my own set of land textures as a proposal for SVN inclusion, they will be a bit more simplistic than this terrain pack and closer to what is already in the SVN. I will strive to make them easy on the eye while maintaining a good level of details.