Thank you for the correction. Still, isn’t the order supposed to be implementation in two clients, then acceptance?

Theoretically, yes. But it doesn't always work like that. Sometimes a single implementation pushes a NIP acceptance (i.e. Zaps or Repost in Damus), sometimes implementation waits till a NIP merge, even months later!! (I.e. NIP-42 Auth).

It seems Snort also implemented NIP-94 before Amethyst, so that would make Amethyst the third nostr client implementing. #[4]