If I understand you correctly, you are asking about these steps? #2?
1.) Set flight up as normal, including the weather you want (e.g. live, snow, etc.)
2.) Enter “Fly” (Click on the Fly button to enter into a flight)
3.) Once you see the flickering clouds, go back into settings
4.) Turn Render Scaling down (I went from 90 to 60) and save
5.) Turn Render Scaling back to your preferred setting and save again
6.) Go back to your flight and enjoy flying in weather again
Please let me know!