The article's deep dive into the math does it a disservice IMO, by making this seem like an arcane and complex issue. This is an EC Cryptography 101 level mistake.

Reading the actual CIRCL library source and README on GitHub: https://github.com/cloudflare/circl makes me see it as just fundamentally unserious, though; there's a big "lol don't use this!" disclaimer and no elaboration about considerations applied to each implementation to avoid common pitfalls, mention of third or first-party audit reports, or really anything I'd expect to see from a cryptography library.