Thanks for the feedback!
Have you tried the "user guide" available at
https://fakinthefunk.net/userguide?
The first chapter gives an overview about the basic concepts...
I'm currently working on an online-feature so that you can upload the requency-spectrum of questionable files and let them be rated by the community. And maybe I can then later include a kind of KI that can improve the results automatically.
From my point of view: lossless files with a cutoff-frequency above 19.8 ore most likely to be good enough to play, but it's always worth to take a deeper look
... The world is full of fake