I really wanted to create a MC server with some fabric mods. I wanted features from the SmartSpawners plugin but I could not find a mod for that... so I made it!
Mining a vanilla spawner with Silk Touch will drop a Super Spawner for that mob. Super Spawners can be placed down to "spawn" mobs without spawning them. Instead of spawning the mob, it calculates the drops of the mob and stores them in the spawner's inventory. A spawner by default can store a double chest of items. Adding more spawners to the stack will add more double chests.
You can add sugar to speed up the spawner with dimenishing returns. Up to 1805 sugar can be added, and this will speed the spawner up from 10 seconds per spawn to half a second.
You can add a Nether Star to the spawner to keep it loaded and spawning while you are far away. Adding a Totem of Undying to the spawner will make it simulate player kills(fun fact! this is required to get Blaze Rods from Blaze Spawners).
Spawners also store XP in an internal buffer.
More updates are planned! I might add a looting upgrade in the future.

