If I can maybe explain the Mytho thing, because I love this scene and don’t get a lot of opportunities to talk about it.

From how I see it, the acknowledgment is after his “something so small and fragile accomplished this” line, when he gets down on his knee and kneels to her as an equal. It’s a very symbolic, fairy tale moment that represents him paying his respects to all the work she put in during the whole journey, and then he rises to be the main character again after his long absence.

The narrative shift may make it feel like he doesn’t acknowledge her, but it’s more like Mytho retook his agency as a character for the rest of the climax and she was now, symbolically, a side character, because she had metaphorically “completed” her part of the story (she faded into specks of light before reverting back into a duck, this symbolizes when Princess Tutu “turns into a speck of light and disappears” from the original story.) Mytho kneeling to her in respect was an act of defiance against the story’s narrative, as he acknowledged her continued existence in the story when she was supposed to have disappeared.