Thank you very much for this article!

I would like to add that by applying some theory from linear regression, it is possible to automatically find the smoothing parameters via Cross-Validation (DISCLAIMER: I wrote this answer).
See https://stats.stackexchange.com/a/648154

Besides, the SciPy implementation has a bug for large polynomial orders and window sizes (state Dec 2023).
See https://github.com/scipy/scipy/issues/20825