Q_PROPERTY containing QList<QGeoCoordinate> doesn't work

Firstly, I want to be able to set an entire MapPolyLine path in one go. Why is the path property read only?!

Second,

Sending a Q_PROPERTY(QList<QGeoCoordinate> .. ) to qml, doesn't work. The value is undefined.

If you use QQmlListProperty you get `Unable to handle unregistered datatype 'QQmlListProperty<QGeoCoordinate>'`

Please explain how this is supposed to work.

I have 2 modes, one is where the points come in one by one, and I use the polyline.addCoordinate method. The second is where I have all the points up front and want to setup the line in one go.