After playing GWE a few times (also applicable to other routes) with foggy weather set, I have to say that the fog seems much too thin and distant. Personally I would love to see a much thicker 'pea soup' type of fog which limits proper visibility to something like 50 to 100 metres in order to really test concentration and route knowledge as sighting signals and signage accurately and in good time will become difficult.
I definitely agree with this. I think there should be a separate weather setting called 'Foggy' where you get poor visibility just like you mentioned. Then for people who want to use 'Fog' they can still use it as I like to drive with the entire sky being cloudy. Maybe they could change the name to 'Cloudy' or something along those lines