The only applications I'm aware of that currently do spectral rendering on the fly are painting apps.

I have one called Brushwork ( https://brushworkvr.com ) that upsamples RGB from 3 to a larger number of samples spread across visible light, mixes paint in the upsampled space, and then downsamples for rendering (the upsampling approach that app uses is from Scott Burns http://scottburns.us/color-science-projects/ ). FocalPaint on iOS does something similar ( https://apps.apple.com/us/app/focalpaint/id1532688085 ).

I'm happy that tech like this will open up more apps to use spectral rendering.