Okay, maybe I'm a retard. I thought extended mode was that?
I've used systems before where basically you can just drag the window in question from the main monitor to the side monitor seamlessly, then hit maximize and it will fill the secondary screen while you can maximize something else on the primary screen (ie front and and back end coding for adding code and testing). Is that extended mode, or am I just mistaken?
Again, sorry, I'm new to all of this