CUSTOMIZE YOUR OPTIMIZATION SETTINGSYou can find these settings right above your HP bar:It will open you this window:Choose only show important models.
+1And also a head hunter + stone for other four cities beside Lost. Lost is always laggy.But to solve the lag you can try:
In my opinion it's useless, as the lag near the teleporter is way smaller than lag in the instance or when killing the boss.
89652684 ppls x 8-10k damage per hit = boss die in second ( many afk),if you feel still problem go quit ur client!!