The 6 Bugs
I recently noticed that there are too many ghasts spawning in the soul sand valley that could potentially make it very hard to have nice gameplay in this biome, I feel like the spawn group value is Okay, maybe ranging from 1-2 (2 is rare) per group, but the spawn probability per chunk is Insane. Every 15 seconds avg I see one ghast spawning, so I think you could make it lower?
There are almost no endermen, only a huge amount of skeletons in soul sand valley.
In the new biome called Warped Forest, I understand how game designers made only endermen spawn in this biome on purpose, but there are way too many of them.
The air color between biomes change too quickly, I think there should be a "gradient" color-changing process.
I know that you triggered the fog everywhere thing when you made these biomes, but do you think that sometimes it blocks eyesight and make everything so blurry?
The original nether biome "nether wastes" spawns like its a rare biome, and every time it spawns, it looks like its always a big lava lake.
Please only report one issue per ticket, also use the search function before reporting an issue. See: Guide: Writing Helpful Bug Reports for Minecraft
Most if not all of these have been reported before.