Fullscreen doesn't make sense with headerbar

In 0.2.4 with GTK+3.12, there's a fullscreen option in the menu. However, this mode doesn't seem to make sense with the headerbar as most of the usable app UI is then hidden away. I can't see a use case for hiding the controls, search, view switcher, etc. and it's not obvious how to escape the mode. In addition, if a search is started (intentionally or unintentionally) by typing, it's not possible to see how your library is being filtered or to easily remove the filter.