Thanks, but actually I don't use Qt anymore, that bug and a few other ones in 5.4 lead me to use Java and C++/CX for the UI, with common business logic in C++, in a MVVM approach.
The approach of re-doing in QML standard UI components is not appealing.
C++ Widgets should be able to offer a mobile friendly version of themselves.
Which was actually a point that was discussed for the Qt roadmap at Qt World Summit 2017.