Switching between buffers activates the slick cmd line.
Starting with a single window and several buffers
Window -> Split vertically
Drag one of the edit windows to a 2nd screen.
Place focus in the edit window in the main Slick window
Now next-window to get to the floating editor.
And the slick cmd line on the floating window is active.
Or, if you start in the floating window and next-window to the docked window, you get the slick cmdline on the main window.