I think that the basis for the survey is flawed, so I haven't completed.
Your assumption is that Flight Sim's weather system gives a realistic perspective. I have always found that MS perspective is nothing like reality when it comes to weather.
It's impossible to compare visibility in MS Sim to real world weather, and the clarity of the terrain vs real world clarity gives totally false clues.
If you want a valid result, you should use real photographs.
dp