Nice, custom prologues and epilogues for FFTs are a welcome feature.

That stuff was in FFTW and cuFFT for many many years. It's one of the features I always pointed to as missing in rocFFT but they've finally caught up.

Yes, it has been in cuFFT for a long time. I thought it's new to python cuda libraries, but no. Turns out it has also been a thing in CuPy for a long time.