Why do you need to heel toe from 1st to 2nd? Just press the clutch put it in gear and shift?

Have you thought about getting thinner shoes? I have $15 Asics wrestling shoes when I autocross. Makes a world of difference when you want to "FEEL" what the car is doing. No other mods will do that.

Also think about getting a 5 point harness. It will keep you in your seat so you can concentrate on driving and not holding onto the steering wheel for dear life.