>> I often right-click to open a separate window,
I like to have two instances of my browser running, so I can have a couple of tabs in a window on my left-hand monitor, and another browser window open on my right-hand monitor with a few more tabs.
That way I can have two tabs open at the same time, and see both by just moving my eyes. Like having two books open side-by-side instead of stacked one on top of the other.
The only way I know to open two instances of the browser is click on my "FireFox" icon a second time, while one instance is already running.