An idea for anyone hunting for plugin ideas, is a Command Block world.
A command block world is a world where you can place command block scripts, and have them execute as if they were running inside another world.
Often in survival you want to paste a CommandBlockModule you see on the minecraft wiki in order to gain some functionality that you havn’t seen a plugin for, but those modules can take up a lot of space, that need to be protected.
Spawning that module in the command block world, would let you keep players out of the command blocks, while the scripts executing inside the blocks are completely safe.