Hey guys, I'm not sure when it happened, but I can confirm that after some Office update, OneNote 2013 now does EXACTLY this by itself (on my Surface Pro 2) :D If I'm set to full screen with just tabs shown in portrait mode, it remains full screen with just
tabs shown the next time I rotate to portrait mode. Same goes for when the entire ribbon is displayed, and when the side-bar is displayed.
Thanks for finally fixing this Microsoft, only took you over 2 years :/
EDIT: That's only a fix for devices which support multiple orientations, ie Tablet only PCs or 3-in-1 PCs like the Surface Pro. Laptop/Desktop only PCs (which obviously have only 1 orientation), you'll still manually need to reshow the tabs when you
manually switch to full-screen mode by clicking the full-screen button. Come to think of it, it somewhat makes sense considering the name of the button.
For Tablet only PCs and 3-in-1 PCs like the Surface Pro, prior to the update, when in portrait mode (in which I take natural hand written notes on my Surface Pro 2), OneNote 2013
automatically switched to full screen mode (no side bar, no ribbon, no ribbon tabs) and never remembered your side bar nor ribbon status, despite it not being you that
manually invoked full-screen. After the update now, when I change my Surface Pro's orientation, it remembers both my side bar and ribbon status when I was in that orientation! So, I could enable full-screen and the ribbon for
landscape mode, and full screen and just the ribbon tabs for portrait mode, and it'll now remember the status
automatically.