Request Description

Use greedy meshing to join alike faces as it reduces V-RAM significantly.
The basic idea is instead of having multiple quads next to each other that are identical, they can be joined into 1 larger quad which saves memory and takes less time to send to the GPU.
Here's an implementation: https://github.com/cgerikj/binary-greedy-meshing, though it (version 2) doesn't use ambient occlusion and it's not written in Java.

Greedy meshing is not feasible in the context of sodium. There's been multiple extended discussions about this topic on our discord server.

See here:

greedy meshing isn't being considered
it is infeasible to implement while maintaining compatibility with mods/resource packs, and unlikely to offer much improvement due to texture rotation and such
the amount geometry that water/lava accounts for in the world is very small, and even in an ocean, not relevant