Crash when QQuickView loads QML document that binds Overlay.overlay.[property]

// RootItem.qml
import QtQuick
import QtQuick.Controls.Basic

Item {
    id: root
    width: 640
    height: 480

    property double scaleFactor: 2.0

    Scale {
        id: scale
        xScale: root.scaleFactor
        yScale: root.scaleFactor
    }
    Item {
        id: scaledContent
        transform: scale

        ComboBox {
            id: combobox
            model: ["Alpha", "Bravo", "Charlie"]
        }
    }

    Overlay.overlay.transform: scale // CRASH!

    Component.onCompleted: {
        // Still cannot assign/bind here. Component is NOT complete!
        console.log("Overlay is", Overlay.overlay) // "Overlay is null"

        //// WORKAROUND OK
        // Qt.callLater(function(){
        //     console.log("Overlay is", Overlay.overlay) // "Overlay is QQuickOverlay(...)"
        //     Overlay.overlay.transform = scale
        // })
    }
}

// main.cpp
#include <QGuiApplication>
#include <QQuickView>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQuickView view(QUrl("qrc:/RootItem.qml"));
    view.show();

    return app.exec();
}