Firstly, I'm having some trouble getting custom textures working for terrain, I'll explain what I did so far.
Basically, I made the textures required based on the location of where I currently am in game, Border Zone I think. I found at least one of the textures that I wanted to replace, SkinnersGravel_DIF and _NML.
The DIF is DXT5 and the NML is DXT1, they work as I've tested them by replacing the base textures in the data folder. ( I learned that DXT5 for NML breaks everything, that's not an exageration).
So here's my issue, I have a folder in the mods folder called "Re-Terrain", and inside that mimics the folder structure for the data folder and where the textures I need to replace are, so it goes: \Re-TerrainV2\newland\land\textures, and the data folder is \data\newland\land\textures, so I believe I've done that right, according to the readme.txt.
Next, I replaced every instance of those textures in every Biome where the textures exist with my own whilst Re_Terrain is active, I'll attach an image below.

Am I doing this correctly? I'm showing Artery as an example, but it's replacing all of the require Biomes, It's most likely that there's another step, but I'm not sure, I'd appreciate any help with this issue.
One more question, does the game not support LOD's? This is honestly baffling if it doesn't, no wonder the game suffers from perfomance issues.
Thanks for reading.