Is there a way to efficiently model the diffraction effects of a Binary 2 DOE in a lens design?

It seems that the Binary 2 applies a continuous phase profile without the 2*pi phase steps. I have looked into using POP with a custom “Grid Phase” surface but the processing is very slow and works for one system wavelength at a time.

I could try to model multiple configurations, but I am looking to model the PSF and FFT MTF of all diffraction modes simultaneously to evaluate image artifacts for a polychromatic source.