Cold biome runs — anyone farming Voidbrine and Mirefen?

The cold biome has two liquids you can't get anywhere else — Voidbrine and Mirefen — plus its own plant set: Frostbloom, Ice Fern, Glacial Moss, Snowdrift Vine, Crystal Sprout, Tundra Reed, Permafrost Lily, Boreal Thistle. I see far fewer players up north than in the hot biome, which either means the loot isn't worth it or it's an underrated farming spot with less competition. Which is it? If you run cold routes: what are you actually farming there, is ice resist gear (Frost Casing and friends) actually necessary or a trap, and does anything from the cold plant set end up in recipes worth caring about?