Control interaction outside on Dialog with mouseUp or mouseDown (with others)

[murm]

Feature request

Overview

I would like to be able to control whether or not interaction outside a Dialog is affected by mouseDown or mouseUp, due to specific needs for our system.
Currently it triggers immediately on click (mouse down).

Who does this impact? Who is this for?

The need is for our users to be able to abort the closing if they do move the pointer inside the Dialog after a click, and a certain need for Jam to work as expected in some testing scenarios we have.