More lightweight system for registering the same Qml types

I was analysing in detail the construction of QDeclarativeEngine. Quite some part understandably goes to registering the Qml types via qmlRegisterType() -calls.

 
61ms QDeclarativeEngine::QDeclarativeEngine(QObject*) (61ms in-thread, 39ms out-of-thread, 100ms both)
 60ms QDeclarativeEnginePrivate::QDeclarativeEnginePrivate(QDeclarativeEngine*)
  16ms QDeclarativeItemModule::defineModule()
  10ms QDeclarativeUtilModule::defineModule()
  01ms QDeclarativeEnginePrivate::defineModule()

(Times presented here are mostly the in-thread times, so in case of asynchronous operations the time spent in other threads is not visible.)

I noticed that almost all of the registrations were done for both "QtQuick" and "Qt" -tags:

 
void QDeclarativeItemModule::defineModule()
{
...
    qmlRegisterType<QDeclarativeBorderImage>("QtQuick",1,0,"BorderImage");
...
#ifndef QT_NO_IMPORT_QT47_QML
    qmlRegisterType<QDeclarativeBorderImage>("Qt",4,7,"BorderImage");
...

The registeration for each type for "QtQuick" takes approx 120-150us (in-thread) inside QDeclarativeItemModule::defineModule(), where as it takes 70-80us for "Qt". I'm guess the element itself is the same for both. So, we can roughly calculate, that 1/3 third of the total time of registering types, goes to "Qt" tag. Could there be more efficient way of mapping also "Qt 4.7" for the Qml types already registered for "QtQuick 1.0"?

ps. Not sure if this is already handled under http://bugreports.qt.nokia.com/browse/QTBUG-15331