Your first and last videos in particular are what I miss from back then. In the Bay Area here, as seen in my photo, the fog is very much that thick white like in your last video. And it creeps in over the mountains.
I distinctly recall racing home from work just to be able to play with Live Weather on because it would mirror it in the sim and there was no historic weather option so the only way to get it was Live. It was magical flying over towards KHAF at 2000’ AGL and seeing little patches of grassy hills poking through the fog.
I’d kill for this to be added back and would readily pay for a weather addon that did this even semi-realistically.
What I don’t get is why they can’t do it now. They have thermal updrafts and mountain currents, they have wind, humidity, temperature, dew point, etc. They should be able to model this just fine, no?