Edit: I didn't see your second post before composing the below. Sounds like you found where to chang

Edit: I didn't see your second post before composing the below. Sounds like you found where to change the default behavior.

On Windows, if you choose "Exit" then Firefox will close everything without warning. The warning fires if you close a single window using Close.

It sounds as though the Mac is similar, where you do not get a warning for "Quit" but you do get a warning for Close?

Are you using menu choices or the red X button on the title bar?