Distribute it as a patch like in dwm since graphical applications usually provide their own keybinding; I guess it's only for terminals.

Note that even though these commits don't let you open multiple windows in fullscreen and cycle between them like in dwm, with just fullscreennotify spawning new windows or changing tag would still exit fullscreen automatically, but you would have to toggle fullscreen twice when switching back to the fullscreen window to enter fullscreen again, so this is better since it avoids that.