Upgrading to OSX High Sierra breaks Terminal hot key functionality On Sierra's Terminal Command1, Command2, etc. would switch between different Terminal windows.  Now it switches between tabs within the same window.  Yes, I could use Command`to cycle between the windows, however, but I want back the previous functionality.
The Terminal settings allow you to escape this hell.

Terminal > Preferences (or Cmd-,) > General:

Second to last item: "Use Cmd-1 through Cmd-9 to switch tabs"

Unselect this option and it all goes back to how it was before!