Need something like prepareGeometryChange(), but without update()

I'm making CAD-like software. It uses graphicsscene for stuff.

There is rectangular tool, that is in scene. User can change geometry of this tool. I use prepareGeometryChange() in method that changes it. This prepareGeometryChange() calls update() automatically. But it is bad behaviour in my case. It is bad becouse it calls update() for old boundingRect() and new boundingRect(), but in fact there can be more optimal way: it's better call update only for space, that is freed and newly occupied places.

So it will be nice, if I have ability to do update() manually when i change items geometry. In other words, it will be nice to have method in scene, that will update it's index without calling update().