Howdy, I've made a video recently going over how to achieve the full diagonal movement that makes Blinx go super fast. This can be achieved with a normal Xbox one controller, (and presumably all other controllers with a thumbstick) making third party controllers not as essential if so desired. (But it might be beneficial in this case)
In short, you need to achieve close to 100% (around 95-100%) in both the x and y axis when inputing a diagonal signal. There's a controller tester on the Xbox One you can download to test this.
You'll want to take off the front shell of the controller and widen the hole on the shell that the left thumbstick rests in. This will allow the thumbstick to have a wider range to move in. The controller shell originally stops the signal from going to 100%. Make sure not to widen the hole too much