xfce4-display-settings: why is there no "Extend to the left"?

At work my laptop is set to the right of my external monitor. Not because I like to but because no other configuration is possible. When I need to extend my desktop I always have to select «*Extend to the right*» (to enable the external monitor with auto-detected resolution) then switch to «*Advanced*» and manually move the icon of the laptop display to the right of that of the external monitor and press «*Apply*». It gets boring when you have to do that on a daily basis. Besides — and I don't know why — the «*Mirror Displays*» button is disabled. The display selection window shows itself right after I plug in the HDMI cable, which is great. If the desktop was extended before I unplug the HDMI cable, it snaps back to the laptop panel immediately afterwards and that's great too. Therefore I need none of the «*External monitor*» and «*Laptop*» buttons. All in all, out of 4 buttons on that panel only one is half useful, the other ones not at all. So aren't there any... plans to add an «*Extend to the left*» button in xfce4-display-settings? Why arbitrary limit extension to right sides? Are left sides... evil?