The main feature of this update is a massive upgrade to performance. Generation should be about twice as fast now.
Many of Terralith's systems have been reworked in order to accomplish this, but in the end, it's very much worth it.

As well:

- The generation of Thermal Caves has been overhauled. Floors and ceilings now use 3D noise, there are patches of andesite, granite and diorite, and the biome should overall have much more detailed (and less laggy) generation.

- Granite Caves, Andesite Caves, Diorite Caves, Frostfire Caves, Mantle Caves, and Tuff Caves now use less precise methods to set their base block. This will result in less ‘sharp’ biome borders, but improves performance dramatically.

- The placement of stone regions in Lush Caves, Dripstone Caves, and Fungal Caves has been changed; you can find granite, andesite and diorite in different spots now. As well, these biomes can now have more than one type of base stone in rare cases.

- The diorite patch feature from Diorite Caves is much more reliable now and only affects blocks that are part of the terrain.

- Several biomes (Shrubland, Brushland, Siberian Taiga) have had their surface rules refactored for better performance.

- Desert Caves have been temporarily disabled for performance reasons.