Quick way to toggle between "Larger Text", "Default", and "More Space" on Macbook Retina
You can use Automator to script things like that since OS X does't include a built in command key for that option. Once it's scripted, you can then assign a key shortcut to that script/action.

Open automator and search for the "watch me do" action for scripting of the UI.

Relevant tutorials are at https://macosxautomation.com/automator/foo.html