For anyone interested in checking out the 2 new underground biomes there's one of each that are easy to get to nearby. The
Lush Cave biome can be found by taking the 2-lane road north out of Bradtropolis until it splits (~ 1030, -240), and then taking the stairway all the way down. The
Dripstone Cave biome is a little trickier to get to - you have to boat or fly out to the 'glitch' ocean village (~ 1800, 70) and swim down the well. I've put a bubble column in to get back up to the surface, but you'll have to hold your breath some on the way down.
Both areas are unlit (except by glowberries and lava) and
au naturel, so be wary of baddies and pitfalls.