Keep the attack/chase distance low.
This is all you need to do a max level purge. Don’t even bother trying to build a defensive base or maze as the NPCS get stuck in them constantly and it ends up making the purge take 3x-5x longer. You can easily solo up to like threat level 6 with good gear. For a max level purge you need around 7-8 BIS geared accursed thralls or better.
Honestly doing it any other way is a complete waste of time as the rewards are absolute dog droppings. Also the rewards for purge level 8-10 are exactly the same the only difference is how many enemies it sends at you. Theres no reason to do above an 8 unless you just WANT to.
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