I didn't see mention of multi-channel? Can you stream 4 x 20/40/80MS/s?

2x 160 can be done pretty easily. Only on same band/LO though. So, only for things like multipath. 4x 80 might be possible, but needs a lot more effort. It is up to 2 ports per icap engine and only one icap engine got coerced into writing to pooled sram. The other 2 could only do their designated regions that are limited to 16KB if I remember right. So continuous reception gets more complicated/precise. Everything above is from me experimenting with HW. There is no official reference for this stuff. So I may have missed something, and some mentioned limitations may be workaroundable.

> when I first saw it referenced I assumed it was

No need to assume, the phrase is literally a link to the blog post the defines it!

If you need to read the linked blog to understand the short phrase then it was poorly chosen and confusing which is what is being discussed.

If you change your Fourier transform approach into a time domain convolution, then you can generate it sample by sample. White noise -> FIR filter, this is a pretty simple and direct algorithm as far as DSP goes. The wiki on pink noise mentions this. I've done the FIR filter approach to simulate 1/f phase noise.