I will try to be more specific in the data, although I might not have all answers in hands.
The material is acrylic (refraction index ~1.49). The light is mainly polarized and comes from a plane which is located under the optical device. I guess that only s type rays will cover the case properly. In my simulations the rays come from bottom to top and from left to right in an angle which is in the range of roughly 27 degrees in the upper limitation line and 45 degrees in the lower ray limitation line (please see attached graphic). Having slope values for the different rays would be fine, but not essential. The way you indicate it with different colors in the existing model is fine.
What is essential for me is the consideration and calculation the rays in concave faces (see attached graphic, where a simple concave polygon appears with a ray crossing two concave cuts; the ray angles are only as example! :) ).
The maximum incidence of concave areas are two subsequent ones.
So, if you consider the specified light (s), the material used, the origin of the rays from one specific plane and the maximum incidence of concave cuts in the polygon it might be easier for you creating the necessary changes in the simulation.
Please let me know if you need further information or data.
Once again, I am more than grateful for your support and interest! The existing simulation is helping me a lot in my investigations.