I have been building a raid farm at around x: 522 z: 531, on the sea south east from the main city. If you want emeralds, totems or some gunpowder, along with the other drops standard from raids, you can use it. It comes with an auto sorting system and a raid captain bank for convenience.
It is NOT a stacking farm (I didn't want to kill the server with too many drops), meaning after each raid you have to restart it manually. Just fall down the empty shaft and get back up using the bubble elevator. Be sure to quickly kill the pillagers, before they heal and the evokers can summon vexes.
This is awesome. With unlimited totems of undying, we have finally unlocked the secrets of Juche necromancy. You've done a great service for the server!