IAmREGE

A client-side mod allows you use custom directories for reading and saving singleplayer worlds.

Add a “Search World” box for MC pre-1.13 || Enhance the searching behaviour

A plugin run on server-side, which allows you to refuse some crafting operations from client-side.

Enable you to override the target main class's Java Program arguments with arbitrary arguments using Mixin (by SpongePowered). And without changing cmdlines(in Task Manager or Htop)!

Command /schedule, but with realtime, and no need to worry about the TPS!