I just noticed this today, I was driving at Kayalami in the FISI cars, and when a car would spin, the only thing you can see through the smoke is the driver helmet, it is like the smoke doesn't affect it. It is like there is a hole in the smoke JUST around the helmet
Hopefully the smoke isn't finished. In an online session the other day the leader laid down some smoke for us going into the last turn at sepang north loop. Couldn't see a damn thing and all of us crashed.
The flyscreen on the F2 cars makes the smoke seethrough, that is above the screen you see smoke, but look through the screen and you can see perfectly.