WOW! I am glad my Creda does not do that. It fills, tumbles once the water level switch is satisfied then stops if it has to add more water, etc like the Mieles. After a timer increment of full washing action, it goes into a heating mode. In this timer increment, it heats for long periods then will do maybe one drum revolution at a crawling speed to just turnover the load, maybe to prevent things from getting exposed to too much heat too early, then it returns to heating mode. It does these heating periods after each of the starting points A, B or C. It heats in stages: X degrees in the heating period after A, X degrees in the heating period after B and X degrees in the heating period after C. Fortunately mine has hot and cold fill valves so I am not heating from cold to super hot.
I guess the other thing you could do to trick a machine like your aunt's and avoid the static heating to 40C is start it at the first rinse then, once everything is saturated, restart it in the desired wash cycle. You do have to wonder what the people who design the machines are using for brains. I certainly felt that way about the 21 & 22 series KitchenAid dishwashers that filled, heated the water then sprayed it on the cold load.