But maybe not this[1] non-linear? Fun if real. But perhaps fitting was done within a gamut folks care more about, and model math then induced artifacts at the margins of the full visible gamut? I'd really love to know if that blue tail represents real perception.
[1] https://www.researchgate.net/profile/Volodymyr-Pyliavskyi/pu... [png] from https://ojs.suitt.edu.ua/index.php/digitech/article/download... [PDF dl] (Curiously, bing image search has this figure, but google doesn't.)