Best way to create part of a mesh that acts as a light source

Are there some limitations with the lights and their includedOnlyMeshes property? I made a test to light the instance (sphere) with point light using includedOnlyMeshes after two seconds and nothing happens. See:

If the original sphere is used, everything works… :grimacing:

Digged into some code and found this:
Could someone explain what this means in laymans terms? If I have an instanced mesh, the lighting of it cannot be changed? :exploding_head: