[pkbo]

I don't have any skills inPython or PyQt so consider below as pseudocode. If you subclass some widget you may override event() method:

def event(self, event):
        ret =  Qwidget.event(self, event)
        if (event.type()==QEvent.UpdateRequest) and PyOnyx.screen.ScreenProxy.instance().isUpdateEnabled():
             PyOnyx.screen.ScreenProxy.instance().updateWidget(self, PyOnyx.screen.ScreenProxy.GU, true, PyOnyx.screen.ScreenProxy.WAIT_ALL)
        return ret

If you don't want to subclass a widget you may install event filter to it and process UpdateRequest event there, onyx/screen/screen_update_watcher.cpp is an example of such filter. It is also possible to subclass QApplication and override notify() method and to update screen there in this case you will not need to worry about screen refresh for every widget.