out of the million things on Freds ToDo list i think (i HOPE!) he concentrates more on ones that are general and that help as many programmers as possible! Your integration request is very specific and while it would help with your project most coders will never have a need for it, and there's nothing stopping you from writing your own to add to your own project? Why does it need to be integrated? Especially when a quick search for FFT or Fourier shows people have already released code for it, here's just one
example 
please dont take this wrong way! I just feel bad for Fred being inundated heehee
