Very cool!
Just a random thing I noticed reading through [1]: you might have a bug in how you calculate the magnitudes of the signals? When you assign the output of the low-pass filters on the high frequency to the input of the magnitude approximator, you assign the imaginary LPF to the imaginary input but the real LPF to also the imaginary input, which I think is incorrect? Since I’m on mobile, it’s easiest for me to show sign a screenshot: https://i.imgur.com/tAQe5Sr.jpg (If that is indeed a bug, I’m curious how that might impact the results!)