I've resolved the problem, at least for my personal use.
If I turn the 2nd monitor on first, and turn the 1st monitor off after, I have no problem:
xrandr --output LVDS1 --preferred ; xrandr --output VGA1 --off
There is still a problem when I turn the 1st monitor off first before turning the 2nd monitor on (meaning both monitors are off for a fraction of a second).
I've resolved the problem, at least for my personal use.
If I turn the 2nd monitor on first, and turn the 1st monitor off after, I have no problem:
xrandr --output LVDS1 --preferred ; xrandr --output VGA1 --off
There is still a problem when I turn the 1st monitor off first before turning the 2nd monitor on (meaning both monitors are off for a fraction of a second).