If the lag is mainly caused by the NPCs, why not make a separate world and move all the quest stuff there? Something similar to FYE I assume. That way, people who do quests can just go to those worlds, and the main worlds would be relieved from the NPCs lag. This could also allow events to be hosted in the main worlds. Halls arena could also be separated into a different world, so that the duelists dont have to face all the laggy stuff happening outside, just like the minigames work