When they are really loose you don't have to turn your heel much. I find that if I anticipate a stop I slide my left foot back instinctively now so that I'm ready.

I feel once at a standstill in my power grips too. Pulled up to an intersection, waited for cars to pass, went to pedal across, it was more incline than I thought and I was not in a low enough gear. Didn't get my foot out in time and I toppled right over. It happens.