Reset xrandr (or: switch off the –scale-from setting at disconnect)

I recently found this topic which helped me a lot by pointing me to the --scale-from argument. I'm pretty happy with the way I can connect my projector now and have the same content displayed on both devices without any panning or clipping.
But unfortunately I don't know how to switch the setting off again after I disconnected the projector.

In my example I have my laptop screen (LVDS1 in xrandr) with a resolution of 1366×768 and the projector (VGA1) with a 1280×800 resolution. After I connect the projector I use

xrandr --output VGA1 --mode 1280x800 --output LVDS1 --scale-from 1280x800

which is inconvenient but at least logical.
But when I disconnect the projector later and want to switch back to only using the laptop screen, I need to do something like

xrandr --output VGA1 --off
xrandr --output LVDS1 --scale-from 1366x768
xrandr --fb 1366x768

which I find very inconvenient. Also I don't know of any possibility to find out if there's a scale-from setting currently in action. So my question is: Is there an easier way for this? Since 1366×768 is the preferred resolution for the laptop screen I would have expected one to exist.