I'm currently using my Samsung tv that happens to have a VGA port on the back of it (the HDMI port is hooked up to my Directv box).
The PC/VGA port defaults to a much lower resolution than what the tv is actually capable of. Bummer. But it helps to prove the concept.
When I extend the displays, I can use separate aspect ratios. If everything I'm doing is windowed, then I have no problem switching the applications between screens other than having to resize the windows. But, if I'm running anything fullscreen: games or VPN, for example, then I can't get the full-screen app to run on the second screen. I need to duplicate the display.
When I try to duplicate the display, I have to adjust the resolution of the SP3 to match the monitor. Doable, but because the SP3 uses 150% scaling on icons and fonts, I have to manually adjust the scaling every time, too, or nothing fits. I have set the scaling to 125% as my default, but even that is hard to get used to. Very small icons. I tried 100% for a couple minutes. I could hardly find an icon with the mouse cursor, much less pen or finger.
So, I'm looking for a monitor that at least has a wonky aspect ratio like the SP3 so I can duplicate the display and not have to adjust the scaling.