All in all when should not to have to scroll a menu to do an action like this one, because it takes too much time, say if you are injured with medkits, you carry a launcher, a gun, a primary weapon, have several ammo types etc... already 5 actions + open door = 6 actions, sometimes it is even more. by the time you figure what to press to open the damn gate, you are already dead or you moved away from the zone where you have the opening option available, which is really frustrating.
maybe you could use a combination of mouvements to enable the opening. like pressing quickly moving forward then backward (double tap speed) or quickly right then left... so on, we would not have to look for the option in this sluggish clumsy menu..