That really is a lightbulb moment. One question, how will you manage the subtitles. Will he start off more or less completely subbed and gradually move away from them? that could emphasise the change, but would be a little tricky in the mushy middle.
Personally I think it would be too difficult b/c the above and also because he’s a (kind of) important/main character, and SW subtitles are rarely given to a character with more than a handful of lines…