I can see why it would be a good idea. I used to be stuck in the wrong heat for several weeks and lapping slower cars is no fun and they dont always move over for you. As a result of this you get tangled up with the slower cars and then ruins your week and then you remain in the lower heats. There's nothing more frustrating
and in my opinion thats not really racing.
Any sort of driver grading would be good (in my opinion) It would result in much closer racing and you wouldnt have the pressure of having to do well every race every week to remain in your heat
That's my view on the subject
Steve