[João Dias]

That is very strange, because real Blancpain racers use the curbs quite liberally.

I do hope they improve the cut penalty system.  The "slow down" penalty creates dangerous situations.  There should be a server option to give a drive-through or time penalty.

My bad, the rule isnt quoted entirely, in the full rule you might get another impression about kerb using. But as it is by now, it seems to me it is way too permissive.. 

"111. The white lines defining the track edges are considered to be part of the track but the kerbs are not. A driver will be judged to have left the track if no part of the car remains in contact with the track. Should a car leave the track for any reason the driver may rejoin. However, this may only be done when it is safe to do so and without gaining any advantage. Drivers consistently crossing the white lines defining the edge of the circuit, whether or not they gain an advantage, will be stopped during the free practices, have their lap time(s) cancelled during qualifying and may receive a “drive through”, during the race. The Stewards of the Meeting can apply any other penalty available. Notifications will be for the car, not the driver."