QQuickItem::clipRect clips QSGNode in QQuickItem::updatePaintNode()

I made a QML component based on QQuickItem. I redefined the QQuickItem::clipRect() method in it in order to clip nested components (childrens) along a certain border, which is smaller than the size of the component itself. In the QQuickItem::updatePaintNode() method I paint a custom QSGNode based on QSGGeometryNode/QSGGeometry/QSGFlatColorMaterial. The problem is that when I need the geometry in QQuickItem::clipRect() and clip: true on the component, the rendered QSGNode is clipped along the boundary specified in QQuickItem::clipRect().

What needs to be done to get the QSGNode to be drawn outside of QQuickItem::clipRect()?