@arvid Sure. Since both texture coordinates and shading normals are treated as float3 vectors in a lot of engines, I can use mapping techniques (designed to translate texture coords) to change the shading normal and effectively rotate the environment around the object. I takeÂ three glossy or anisotropic BSDFs and multiply their base colors by FF0000, 00FF00, and 0000FF respectively, then add them together. That lets me rotate R, G, and B independently, and get a sort of dispersion effect. Like most hacks, it's very un-physical, but it looks good in a lot of cases.
One thing to be aware of is that rotating the normals too much can cause black artifacts, like so: There's only so much wiggle room for hacking it before the camera simply can't see the part of the object you're trying to rotate into view, so it just returns null. On this test sphere, I was getting about 3-5° of offset before the borders got too bad, which is more than enough to make an extreme dispersion effect. The fourth image has RGB rotated ~2° each in three different directions.