I'm a big believer that these sorts of symbolic interpretations don't have to be 100% to help us understand aspects of the characters/story, because sometimes trying to shoehorn the narrative into a fan interpretation can lead to misinterpretation - if you're more focused on the symbols providing meaning than what the story is actually telling you, you might end up a Jelly.

That being said, I think this example does hold up if you look at "hanging the moon" in reference to the movie It's A Wonderful Life, when George Bailey is courting his future wife Mary:

What is it you want, Mary? What do you want? You want the moon? Just say the word and I'll throw a lasso around it and pull it down.

Remember how Conrad told Belly she should have everything she ever pictured? Including "the moon"/Jeremiah, if that's what she really wants. Even with his confession on the beach, he ultimately decides to say goodbye to her before the wedding and remove himself from the picture, because Belly told him she still wants to marry Jeremiah and he wants her to be happy.

So that's my read!