This will move the Dock in dual monitor setup for OSX (only tested on High Sierra). When mouse is on left monitor Dock will be moved to left side, else to right side. Best works if Dock is auto hidden.
This tool uses http://www.hamsoftengineering.com/codeSharing/MouseTools/MouseTools.html
Whenever the mouse x position is <800 pixels we move the Dock to the left, else to the right.
Clone this repo in some location. Then
cp script.scpt.env script.scpt and adjust path in it.
Also adjust the resolution depending on your desktop.
cp osx_dock_multi_monitor.plist.env osx_dock_multi_monitor.plist and adjust path in it
Then to start or stop:
launchctl load -w osx_dock_multi_monitor.plist
launchctl unload -w osx_dock_multi_monitor.plist
osascript script.scpt to run script manually