Maximised windows' title bars appear at the top of the physical screen in Ubuntu

[calebplum]

I am planning to purchase a 4k monitor and I'm testing fakexrandr to see if it can help me manage my huge workspace. I have it configured it in a 2x2 grid, resulting in four fake displays on one physical monitor. Ubuntu's menu bar runs the whole way down the left side of the screen, which I like.

When I maximise a window in any one of the four fake screens, the window is sized correctly but its title bar moves to Unity's menu bar at the top of the physical monitor. I believe if the machine had four physical monitors connected in the same configuration, maximised windows in each monitor would have their title bars appear at the top their respective monitor, not on the top two monitors. Is there any way to replicate this behaviour in fakexrandr?

In the following screenshot all three maximised windows should have their own title bar but instead they share the menu bar at the top of the screen:

I've tried changing Ubuntu's Appearance settings to "Show the menus for a window in the window's title bar" instead of "In the menu bar" but it doesn't change the behaviour.

I'm currently running xrandr on Ubuntu 16.04.2 with kernel 4.8.0-36 in VirtualBox.