Use Juno release. I have a laptop and often connect an external monitor to it. When an external monitor is connected, I make it primary.
I added hotkeys/commands:
Win+PageUp: xrandr --output eDP-1 --primary Win+PageDown: xrandr --output HDMI-1 --primary
It works well. But Dock (Plank) move with delay. Can I fix this? Add command for Plank?