So far we've only considered paths through the corner in which the traction of the tyres are used to either brake, accelerate or corner. The fastest approach to a corner will involve a little combined braking and steering at the entry to the corner, followed by acceleration combined with steering as the corner unwinds. While braking/accelerating the corner must have larger radius than when the tyres are providing cornering force alone, otherwise the total traction vector will exceed the traction limit, and the car slides into the gravel trap.
Ideally we want to keep the traction force always at the limit of the traction circle, making a smooth, continuous transition between braking cornering and accelerating. This is the ability that makes a great driver.