To me, the worst fog is when we first arrive in Broken Valley, but after you enter or bypass the village everything looks considerably better. I don't recall it being too noticeable anywhere else, and Aleroth looks great in FoV.

That one patch of fog makes my eyes water, and I don't even suffer from pollen-related allergies.

I'd rather see the blur removed from dragon flight though. That's silly, but probably done to enhance performance.