Is it possible to render widgets on top of OpenGL-enabled QLineSeries?

[InverseTransform]

If I use QLineSeries with setUseOpenGL(true) in a QChart, the series will always be displayed on top of everything else, and setting Z value won't have any effect. According to documentation, that is because:

"When a chart contains any series that are drawn with OpenGL, a transparent QOpenGLWidget is created on top of the chart plot area. The accelerated series are not drawn on the underlying QGraphicsView, but are instead drawn on the created QOpenGLWidget."

What this means is that if I e.g. add some widgets or QGraphicsItems to the scene:

chartView->scene()->addWidget(someQLabel);
chartView->scene()->addEllipse(...);

they will allways be drawn beneath the series, which is really annoying because you cannot have e.g. text label shown on top of the series.

Is there any way at all to have OpenGL-enabled series with other items drawn on top of it, i.e. to control the Z order of the items?