I'm currently on the Reconditioned Relic quest of the anima questline, and I'm having trouble grinding the necessary materials to complete it.

What would be the best way to farm both the Crystal Sand and the Umbrite? So far I've tried the levequest route with gathering Vilekins, but not all runs bare the fruit of treasure chests, and it takes some time to resupply the leaves needed.
And it seems most guides written for this quest were written at the time of launch, so I was skeptical as to which content to farm for both poetics and mats to trade in for the sand.

Any advice for someone who is either currently running the relic quest line, or has recently completed it?