In Ubuntu 18.04 Bionic Beaver with GNOME 3
org.gnome.desktop.wm.keybindings is the path to manipulate default window management dconf variables.
Inside this path we can find
toggle-above variables and set a keybinding to them. However in which aspect they differ?
Testing it I couldn't observe any difference. For both cases, when the equivalent keyboard shortcut is pressed, the active window is set to keep always visible on its workspace, that is, it remains above all other windows on the same workspace.
Is there some discreet behavior that differ this two actions?