Meteor is designed to support the newest stable releases of Minecraft. Latest (1.21.1)
While the client itself is difficult for servers to detect directly, individual "blatant" modules (like high-speed Fly or Scaffold) are easily caught by modern anti-cheats that check for invalid player movements. Pros & Cons ManInMyVan/meteor-archive - GitHub Meteor Client 1.21.1- 1.20.6 -- 1.16.5
One of Meteor's greatest strengths is its wide version support. Meteor is designed to support the newest stable