Don't worry about the Start/Stop function.
The system works pretty well. The engine turns off IF you put it in neutral and release the clutch.
If you keep it down, the engine won't turn off and you can take off immediately.
And if you sense the lights are about to turn green, you simple put your foot on the clutch and the engine starts again.
You CAN turn it off with a simple touch of a button.
It doesn't work if the engine isn't hot enough and it doesn't work if the temperature outside is below 3°C
Hope this info helps, it works great on my BMW 1