@nuno1980 RE: Not dispersion, sorry. But yes diffraction in retro-reflectivity?

I see, well, while dispersion has been supported in Octane for a while in some materials, diffraction has not been - until now with the Physical Optics material - which has not got support for retro-reflectivity.
So ...

@non1980 RE: Does Retro-reflectivity have the "dispersion" (in thin- or micro-refraction) option?

If by that you mean to ask how does retro-reflectivity "interact" with dispersion or thin film, then - it doesn't, currently.
Retro-reflectivity only affects specular reflection while both dispersion ...

To add to what Roeland said, I've managed to demonstrate this working in Cinema4D, with a plane with camera-position projection used as UVs with a modulo of 8x4 to get the desired grid repeated: