Auto Toggle MacBook Internal Keyboard

I prefer using external keyboard with my MacBook. When no external monitors are used, a typical setup is placing the keyboard above the internal one, so I can still use the internal touchpad.

But sometimes the external keyboard may press some keys of the internal keyboard. There is a solution to disable the internal keyboard, but it is tedious to run the command manually.

# Disable, ignore the warning
sudo kextunload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTCKeyboard.kext/
# Enable
sudo kextload /System/Library/Extensions/AppleUSBTopCase.kext/Contents/PlugIns/AppleUSBTCKeyboard.kext/

Fortunately, Keyboard Maestro supports executing scripts when a USB device is attached or detached.