You still on zandalar these days?

I also found the most effective grind for me was simply park the 4 locks on a corner. Send the 4voids around to pick up 5-8 mobs depending on levels. Set them to passive to come back to the locks. Preshield priest. Bind hellfire and prayer of healing to the same button and spam. If it’s a little hairy you can force a holy nova inbetween the prayers of healing due to spell batching.