So many people have already talked about this but , in my opinion the new caves are EPIC but there is also an issue with lighting up the caves and my suggestion that "glow licin" spawns more frequently in caves because it will be a nightmare lighting those caves up, also I think you should do some more work on the diamond generation because if you would take a night vision potion and vent caving you would come out so rich with diamonds and other ores....

PS: I love you guys and keep up the awesome work, I am really exited to see how the 1.17. is going to look in the end <3