Making clouds with Mantaflow, and scattering them with geometry nodes.
I had two lighting setups, one for midday and one for sunset. The final image above uses both in the compositor. I then had to clean up the weird artifacts you can see in the top center of the two renders.
Pretty surprised by how well geometry nodes handled volume VDBs; I half expected it to tell me there was no geometry to distribute. Still have the horizon issue. There appears to be a hard limit to how far Cycles will render. Even if you set the clipping distance out to a million meters, and have objects there, they won’t show up.