Here's the URL to get your Google+ Notifications Full Screen.
Be sure to bookmark it!
As far as I can tell, there is no other way to get the full screen version of Google+ notifications.
It used to be that Google Notifications at the top of the Notifications box was a live link to a full screen of notifications.
But no more ... (or am I missing something?)
I much prefer the full screen option for notifications when I'm browsing on my Chromebook, laptop, and desktop. And using J and K to maneuver up and down from post to post, makes the Google+ experience even more luxurious.
• Twitter (click on tweet to start)
• Facebook (click on a post to start)