I’d argue that it’s incredibly important to the themes and characters. Leia draining her life to Ben is just bare-bones plot; the reason why she’s doing it is that she believes there’s still good in him. In fact, I think her sacrifice is what really pushes him to finally reject the Dark Side completely; so in that sense, “Never be afraid of who you are” ties up his character arc in a nice little bow. And that, of course, ties into the overall theme of “You are who you choose to be,” which I think is at the heart of the Sequels.
I based mine on TFA dialogue, I think. I thought that was Carrie’s most naturalistic performance (her voice sounded a bit weaker in TLJ); and the TROS scenes were just unused TFA footage anyway. That said, if you got better results with your voice, I’d be glad to give it a listen! You do have a good track record with the AI models, after all. 😃