1.16.2 and 1.16.3 changed a lot of things about biomes. Here's a basic checklist of what needs to happen for 1.16.2 and 1.16.3:

• Biomes API: FabricMC/fabric#1053 was merged on September 18, porting the old API.
• Terraform: A lot of Terrestria depends on Terraform. There is a stripped down version of updated terraform included in TerraformersMC/Cinderscapes@95042d4. However, we need to get Terraform properly updated in order to move forward with Terrestria.
  • How we should do the port is an open question. It's possible that the best way would be porting Terraform piece by piece in a modular fashion.
• Begin porting Terrestria: Terrestria runs and compiles on 1.16.3 right now.
• Fix the biomes: Many of the biomes are missing trees and other decorations, these need to be restored.
• Fix the generation: We need to restore the OverworldBiomesExt API in Terraform. Until this, the volcanic island and caldera will not generate properly.

Obviously this can be expanded on, I just want to get some stuff down and have a central place to get updates on 1.16.2 and 1.16.3 update progress.