Nope, doesn't seem to work. I get all kinds of errors when trying with that.

Edit: oh, btw. Readme which came with the shaders says "by changing the material name to mat_model it will automatically be applied to all models."

With that and renaming (no idea what this would change, just testing :P)
bmap_to_cubemap(mat_ToonShader.skin1); to bmap_to_cubemap(mat_model.skin1); actually got the game running, but I can't see any difference on the models. Renaming only the material name to mat_model gives the same errors as earlier.