I do like right-click context menus for advanced features since they do not confuse new or less technical users. The problem as you mentioned is feature discoverability.
You can break out any of the dock widgets into their own window. For example, left-click and drag on the Multimeter dock widget bar, shown here:
You can then undock the widget and move it to your second screen, like so:
Double-click the “Multimeter” Window title bar to redock the widget.