On a street car with a stock brake system, the brakes can very well go away from one corner to the next. It happens plenty at track days. Usually the cause is boiling brake fluid that causes air pockets in the lines. You push the pedal to the floor and you get nothing.
But, Like Mykl says, with a car that is properly setup for racing with super high temp capable fluid and pads, you should only see fading over time as things get too hot.
If you watch racing at all though, you do see most drivers reach over and tap the brake with their left foot while going down the straight, especially a long straight with a tight corner at the end. They are checking for a soft pedal and pumping up the pressure. Do you think they would do that if brakes didn't just go away from one corner to the next? It doesn't happen all that often, but it does happen. (Or you can have a brake disk explode on you like happened to Johnny O at Sebring in the Corvette a few years ago)
I do want to see brake heat modeling. I think we can use sufficient visual indicators (the ones that Tristian normally hates, but seems to be in favor of in this case
) in the interface that we can manage the system.