I'm in the exact same boat (can't snipe/last word, so no lighthouse for me) and find it unacceptable that the response to the many people who struggled and finally managed to achieve the hardest thing in the game is: "Sorry, it'll unlock on your next trip to the lighthouse" as if we can just snap our fingers and go back. I really don't understand; I have the emblem, an adept gun, the Osiris card which can only be obtained via the lighthouse chest. How hard can it be to retroactively award this?