Without having people Shift+U'd at the points in question, how can you identify if someone has cut at those points of the track, and even then, how do you void the time they put in if they dont realise or carry on regardless?
Red zone areas would be a little extreme, but would solve the problem in an instance, no additional eyes required, no ifs buts or maybes about it, if you enter those areas then your clearly off the track.
I saw a couple of people driving through cones and carry on and put in a faster times yesterday, one of which clearly knew it but carried on regardless. Clipping one and not noticing because your focused on whats ahead is one thing, but whatever extent it is, how do you stop people from blatently ignoring the cones as they're a movable object with no deterent unless you spot them, and even then how do you null a submitted time, you cant remove it and take the next best time.
I agree with the reason the layout is there, theres no problems with that, however what i dont understand is that you've decided to act against people who cut by placing something down to clearly identify who's pushing their luck, but i dont understand what actions can be taken to right the wrong. How do you police the cutting rule? Currently you know who's cutting, but how do you identify it when it needs to be, and what action gets taken.