By the way: For Tonemapping purposes I highly recommend to use https://www.videohelp.com/software/DGDecNV .
libplacebo is quite popular at the moment, but in results not much better than other standard conversions.
You can actively adapt parameters while watching what happens, and take the best parameters in to Avisynth. To me by far the best way. Maybe all scrreenshots I saw here went through libplacebo, then I understand, what happened.

Edit: Our postings crossed…

Unfortunately the German dub also has the “original” English opera texts. Especially the Zauberflöte-papageno aria I know quite well (a good friend sang it many years ago) and the English text is quite horror to me. I second this.