Placing a QWidget on a QGraphicsView - what's the difference between the 2 approaches?

Question

Qt

Good afternoon!

I want to place scene controls on QGraphicsView. Like these
Controls should be stationary and not change scale when the view scale is changed.

Found 2 possible ways.
one.

QGraphicsView* view = new QGraphicsView;
MyWidget* mw = new MyWidget(view);

2.

QGraphicsScene* scene = new QGraphicsScene;
MyWidget* mw = new MyWidget(view);
QGraphicsProxyWidget* proxy = scene->addWidget(mw);
proxy->setFlag(QGraphicsItem::ItemIgnoresTransformations);

What are the pros and cons of the approaches? Which one should you choose?

Or to create such controls in general differently somehow?