Overview: allow to navigate monitors using keyboard
Currently there is no way to switch monitors using the keyboard in the overview.
Cinnamon uses Tab to switch monitors and arrows to navigate windows in the current monitor, but I think extending the current directional navigation features to include monitors would be more intuitive (for example, pressing up to go to the next monitor up). Analogously, Tab and S-Tab could be extended to cycle the full set of windows.
Those are suggestions, but any way to switch monitors using keyboard will be a great improvement over the current situation.