To view an edited video in a full screen is enough to use hotkeys cmd+shift+f.
But functions of this mode can let you do the other things. All elements on Screen Controls are appearing and operating in full-screen mode. If you using a laptop for your work then it is really necessary functions.
A few examples:
correct a horizon: Transform(sift+t).
The digital zoom or to adjust a composition: Crop(shift+c).
Distort(alt+d). Keys to zoom (CMD-[+/-]) are working too.
Pay an attention to the buttons in the upper left corner of the screen.
Management titles and templates of Motion. Just clicking mouse and type!
is working too (buttons 1-9), if you remember a size of each camera. Next one (alt+[1-9]) & of course CMD+Z.
Of course it's not a lot & a little damp (for example doesn't work shift+z), but you can imagine the possibilities of the work in full screen mode that's waiting for us in the future. I hope.