It's not possible to visually alter the stacking order of items with same Z level

When using the visual QML editor, creating e.g. a TextInput item, then a Rectangle - with the intent of having the Rectangle behind the TextInput without embedding the TextInput inside the rectangle, the Rectangle obscures the TextInput because it's declared after. Being able to right-click in the visual designer and say "send to back", "bring to front" etc would be useful in such scenarios.