As is, the Toon Standard shader has the ability to use detail textures and normal maps. The detail albedo can be set to use a variety of blend modes, one of which includes using a mask texture. However, this seems to only impact whether or not the detail albedo uses multiplicative or additive shading.

One feature about Standard Lite that’s really nice is that you can have a universal mask to hide detail textures, both albedo and normal, from any part of the mesh you want. It would be incredibly helpful if a similar setup was added to this shader, as right now there is seemingly no way at all to mask detail normals, which seems like a no brainer given detail normals are usually small tileable textures you only want in specific areas.