I have been playing with the new crystal wall and lights.
What I have found is that the crystals are mildly reflective and highly diffusive. So putting them behind a light source amplifies it a tiny amount, and has some minor effect. Putting them in front makes the light bigger, and the crystals light up, but it does not seem to be much brighter.
Anyone else trying anything here and had much luck with it? Here is 4 walls around a moder tear at night:

https://steamcommunity.com/sharedfiles/filedetails/?id=2613451157