I have two monitors. One is my iMac's 5K display, and the other is a Dell 1440p display (both are the same aspect ratio). With Minecraft, I can stretch the window across both displays without setting a real resolution and it looks pretty cool, but I think it's probably one of the only games that allows me to manually drag the window from one side of the monitor to the other. Otherwise, you're supposed to use AMD's Eyefinity setting. Unfortunately my Radeon Pro 580X graphics card doesn't to support "Eyefinity." So I had the thought of setting the games to a "fake" resolution recognized by the game—or any fullscreen app really—so it would stretch across the screen like Minecraft even though the monitor is technically neither ultra-wide nor supported by Eyefinity.
So my question is: is there a way to "spoof" a 5120x1440 resolution so games will think I have an ultra-wide monitor? This can be on either Windows or Mac as I have a partition for both.