I think the problem at this point is that the behaviour of the atmosphere is different for terrain and sky. Terrain that is far away enough should be affected by the same parameters as the sky, In this case if you want to have the additive saturated blue haze as we have now in the mountains, you should have it also in the sky.
Now the haze is additive in the mountains and then magically it's subtractive in the sky, creating that disconnection. I did a quick test to illustrate my point. I think it shows how the shaders affecting sky and terrain are disconnected. I this particular option I've blended the sky getting the tones and values of distant terrain, but I could have done just the opposite.
I wonder if its methane smog instead of water
