Applications include laptops , which can be powered whilst charging .
It has outputs for battery and load with current sensing resistors in both arms and so can reduce charge current if need because if the load draw .
Bit below mentions it too.
Useful device as with a “normal” charger you can’t do that
As soon as I saw the statement about not overloading the wall adapter, I knew there was only marketing BS in the information. There is NO way that design knows anything about the attached wall adapter or even is one is being used.