Cameraman

the Cameraman mod allows for another player or instance of Minecraft to port to record replay/flashback files for you without having to have the mod on your instance.

This means that if you want to have a more optimized recording or if you want another computer to just follow you around, this mod is perfect. The way it works is you type /follow player name, and every few seconds, it'll teleport you to that player to make sure they're always within render distance, which is perfect for flashback or replay recordings. Another feature is that it automatically teleports to the player as soon as they change dimensions or any other events such as that.

The mod is really simple and only needs to be on the server for it to work.