It would be a great “new feature” to make the users earn real state screen.
And i think the cost of doing it would be small in terms of time.
Copying hide top bar code and configurations, being able to change the delay, and where to put the mouse / touch to have the menu displayed back, or just put the 3 lines in a corner, to show tabs + address bar + hotlinks would be great. And of course there are better options to do it.
Adding also options for having the tabs and bookmarks (hided or not) at the right of the screen vertically to fast click to switch between them will make a big real state earn, as vertical is almost half the wide, and we would have 2 lines less up in the worse case (without hiding) earning almost a line in total space and 2 in the horizontal one, that is a lot.
Having a bookmark web page as welcome page, would also be a great savings in bars real state saving.