I wanted to texture my MDLs like terrain, too. You know, with vertical rocks on which the texture is not streched or in case of a blendmap not hard to paint on.
And with unlimited textures.
So I modified the fixed function effect of the acknex template shaders. Of course, if you use a lot of textures it will be slow. But you always could /should slice your terrain-MDL, especially for lod iusses.
Here a small tipp, if you want to have cliffs with non streched textures or artifacs and no bad mood while you are painting on it, you could use UV relaxing. I am using 3dsmax at work, there is a nice function that let's you relax the texture within the uv 0-1 bounds. So the points of the mesh are planar. It works pretty good. But I don't know if Blender has such a function as well. I always hated the interface of Blender ... And the tutorials - Hey look at that, see how easy it is only press this button and this other button and press a lot of keys to do this and that - what the hell ...
Perhaps the tips are helpful for somebody. If not, just ignore me