MobLimiter also offers spawner modification protection to prevent unwanted changes to the mobs a spawner produces, as well as mob age locking for when you want to keep your baby a baby forever. Configuration General Settings radius: The "view distance" to check for mobs, as a chunk radius (...
Make a hole where there is no water. Make sure it is not so deep to where it kills the mobs, since this is an XP farm, not an item farm. Clear out an area down below where you will stand as you attack the mobs. By the way, placing a torch on the spawner until you're ready...
spawner_offline_persistence=259200 These values are rather conservative because, unlike for the other type of spawn mechanic, there's no obvious sign that the mobs are being spawned inside of a farm, at least based purely on the spawn/death rates, and also because spawners already have their ...