4.7.0+1.21.8-forge

Fixed: LOD downloads over the fast path (the backchannel) failed with HTTP 404 for every region when the server sits behind a reverse proxy, Velocity or a Docker port mapping, and the client fell back to the slow in-band channel (mod_support #50). The download token was tied to the IP the player joined from, and behind a proxy the download request arrives from the proxy's address instead. A token now belongs to the player alone and lasts for as long as they are connected. Knowing someone's name or UUID still gets you nothing: the token is 256 random bits the server hands that player over their own game connection, and it stops working the moment they leave.
New: once a client has everything within its own render radius, the server keeps sending it the LOD beyond that radius, nearest first, doubling the distance on each sync poll until it holds what the server has, up to 16384 blocks (mod_support #45). What the player needs now is served first, exactly as before, and the next ring is only sent when the client is idle, so it never competes with the first download. It is on by default. Turn it off with /cs set lodBackgroundSend false (lod-background-send: false on Bukkit/Paper) to serve only the area a client's renderer draws around where it stands.

Chunksmith