Just keep it to a few stacked layers—no more than three. Use a height map to carve the ridge, then split the mesh into two or three bands, each one a single material slot. That way the GPU only handles a handful of vertices per band. Drop any unnecessary bevels, use hard edges only where the ridge actually turns. If you need a texture bump, bake a normal map instead of adding geometry. In the end, if the ridge still feels heavy, ditch the extra detail; the landscape will still look right and you’ll save a ton of verts.