It's been mentioned before but I haven't heard any of the devs say it's on their current list of enhancements.
In any case, whilst it seems to work for real F1 it wouldn't add anything to iGP. There is rarely a big enough gap for anyone to do a tyre stop and come out on fresh set of SS without losing track positions. For example would you prefer to finish 4th (12 points) or pit late in the race, get 1 point for fastest lap and 2 points for 9th place? Worse still, you might set the fastest lap but not even receive the bonus point because the pit stop places you outside the top 10.
Finally, in iGP you have the option to save all of your boost to deploy in one lap. The point for fastest lap would encourage managers to save all of their boost until the last lap... a race strategy that doesn't need any more encouragement LOL.
The points system is fine as it is. The developers have other things to do not change points systems. Sure it would change a lot of people's strategys especially the lower level elite who have just got promoted, but it's fine as it is. If anything the qualifying system should be changed for example the randomness of end season. But I don't have many ideas for that