Steps:
1. Open attached project in comment
2. Open repro scene, hit play
3. Click on the 2 buttons on the left, which sets the maximum shader LOD

Actual result: Game View stays red no matter which button is clicked
Expected result: Game View = red if button 300 is clicked ; yellow if 200 is clicked

Reproduced in:2017.2.3f1; 2017.3.0f3; 2017.4.2f2; 2018.1.0f2; 2018.2.0b3, 2018.3.0a8

Note: it seems if the shader is used on normal objects, like the sphere in scene view, shader LOD works fine