Unity3D Shader LOD Stuff

Unity3D Documentation:

• Shader LOD Values
  VertexLit kind of shaders = 100
  Decal, Reflective VertexLit = 150
  Diffuse = 200
  Diffuse Detail, Reflective Bumped Unlit, Reflective Bumped VertexLit = 250
  Bumped, Specular = 300
  Bumped Specular = 400
  Parallax = 500
  Parallax Specular = 600
  
• Global Shader LOD Setting

Shader Forge:

• Shader Forge Subshader Workaround
  "There's no way to make subshaders in SF at the moment, but you can define a fallback shader and specify the LOD level"