Villager Optimization
Optimized villagers will still allow them to be leveled up and traded with but otherwise disables their AI, reducing associated lag. Optimized villagers will not be able to path find (walk around).
To optimize a villager:​
Nametag: rename a villager with a nametag to one of the following names: NoAI, Trader, DisableAI, Optimized
Names are not case sensitive and name tags with these names will not be consumed on use.
To unoptimize, rename the villager any other name.
Command: Use the command
/optimizevillagers <radius>or/unoptimizevillagers <radius>.
Each villager can only be optimized and unoptimized once per 5 minutes.
Breaking the job block of a villager that hasn’t been locked in (traded with) will unoptimize them.