Here's a pair of screenshots of the terrain textured.
The method used in the pictures is a 2048^2 colormap, 1024^2 rgba blend map, and an rgba texture containing four detail textures in the channels. Pretty much a straightforward implementation of "Dot-Product for Efficient Detail Texture Mapping" by Renaldas Zioma in ShaderX 4. Four textures total. Golden rule of not allowing compression for the rgba detail image applies. Rainbows just don't compress well.
From way up there.
Close up of a soft detail texture meeting pebbles.
Code:
GLSL code
vec3 colMap = texture2D(tex1, texCoords).rgb;
vec4 blendMap = texture2D(tex2, texCoords).rgba;
vec4 blendTex = texture2D(tex3, texCoords*300).rgba;
float detRes = dot(blendMap, blendTex);
_______ = colMap * detRes;
Oddities are that a 1024^2 colormap actually looks better than a 2048^2, noise issues. Also still having a considerable amount of trouble getting the terrain to actually use my heightmap. In hindsight, a uniform could be used to individually adjust the intensities of the detail textures.
EDIT: Colormap and blendmap made in L3DT.