I have installed several dishwashers for friends and find them fascinating. All of the ones I have seen basically dumped the contents of the closing soap compartmens as soon as it started washing. Some dishwashers (looking at bosch) even have a little tray in the upper drawer that catches the pod.

It depends on the cycle for some. Mine one doesn't do a prewash for the 45mins QUICK cycle. But the ECO cycle does follow the normal prewash-then-wash process as described in the video. Hence I normally use the ECO cycle and put the correct amount of powder in both components. However in a hurry I sometimes just use the QUICK cycle and only use the main component as I know there is no point in adding more. The manual explained all this.