The following link demonstrates the reflection and refraction on a blurred glass prism (textures blurred, rest is transparent): https://playground.babylonjs.com/#RJN64I
The results are great except for:
Both reflection and refraction are large in size and low in resolution
The prism acts as more like a lens, considering the movement of reflection/refraction relative to the actual object.
@Sarped_Cirak, we are having an internal conversation about how how to control the size of cubemap.texture within refraction. I will ping this thread back soon once we have an answer.