Now couple QWidget::saveGeometry()/QWidget::restoreGeometry() works only for top-level widgets. It can be used for widgets which have parents but with improper result. In this case widget will be moved if screen has toolbar on top of it. Restore process uses absolute display properties to calculate widget position. But this does not give abt warnings while project assemling.

My suggestion is - extend QWidget::saveGeometry()/QWidget::restoreGeometry() for widgets which have parent widget. For this it is needed include marker "hasparent" to QByteArray geometry returned by saveGeometry(). If this marker is found while restoring in QWidget::restoreGeometry() then it restores widget geometry as it works in relative parent position, not desktop.