one caveat is that (AFAIK) if you are doing optical simulations in your rendering, like prisms or glass, the spectral rendering would produce more accurate caus

one caveat is that (AFAIK) if you are doing optical simulations in your rendering, like prisms or glass, the spectral rendering would produce more accurate caustics/reflections/refractions. But to be fair, most realtime rendering is not doing that. I could imagine it being important for stuff like CG films.