Sorry, I do not see any benefit from doing that. Could you explain?

In your internet browser you don't follow the link immediately as you press your mouse button. The link is being opened as soon as you release the button. I followed this common workflow.

Dmitry

The drawback of your approach is that currently clicking a Node deselects the previous one, and you must wait until releasing the mouse before the new one gets selected.

So you get an intermediate state in which the previous one is deselected and the new one not yet selected.

I have in my application a QWidget that shows the "properties" of a Node when it is selected, and I'm plugged on the selectionChanged() signal of the scene.

With the current behavior, I see my widget empty on click (because selectionChanged() is emitted for an empty selection) and filled of release (another selectionChanged). So every time I change Node there is a "flickering" because of the intermediate state where no Node are selected.