One button puts a map tag on everything the game has generated, even in black areas you haven't explored: the middle of every resource patch, the middle of every cluster of enemy nests, and the nearest shore of the lakes nearest you. Helps you find resources you may need desperately. Tick what you want marked in the shortcut's window; Shift+H marks without opening it.
Providing the player with new tools or adjusting the game interface, without fundamentally changing gameplay.