shadow visibility does not work

[aoktar]

" It's about some optimisation for generating less meshes for case but this is not fine for emissive geometries."
So what does this mean in my case?

I don't think it's about your case. Just an explanation for that. Plugin will not export meshes when opacity=0. General visibility or display tag opacity is same.
As i said pls put a scene to let me understand better. Your last request is also not up to me. We can't do somethings if renderer doesn't support.

[alexchopjian]

I ran into this same issue with an OctaneLight. Tons of messing around got me nowhere until I realized the "Alpha Shadows" checkbox was unchecked in the render kernel for Path Tracing. This worked for me!