The addition of vertical tabs is a great new feature. I think the sidebar should be hidden when in fullscreen mode (F11 on Windows). The horizontal tabs are hidden in fullscreen, I think only the tab content should be displayed.
I agree. Like the new feature since I'm hopping back and forth between my phone and computer so much at the same time, however, I would LOVE for the option to have the sidebar disappear when entering fullscreen mode via F11
I also support auto-hiding the vertical sidebar when going fullscreen.
Oftentimes when there is content that I want to view in complete fullscreen, I often used to:
enter fullscreen
turn off vertical tabs
hide sidebar
Then when I'm finished viewing in fullscreen, I would re-enable vertical tabs.
Later I found that the setting 'Hide tabs and sidebar' under ''Customize Sidebar' > 'Vertical tabs' will make the sidebar immediately hidden without tab icons, but then clicking 'Show sidebar' (Alt + Ctrl + Z) in the toolbar will re-appear the sidebar without disabling the setting. This means that with the setting enabled, the sidebar can be completely hidden (or shown) using 'Show sidebar'. I think this setting's description could be slightly be descriptive than 'Hide tabs and sidebar' because I thought it was the same thing as 'Show sidebar', but really they seem to have distinct functions.