Thank you!
As of now, I'm uncertain when I'd come back to this project. Architecturally, there are many parts of the code I'd want to fix before building on top of it. I coded as I went which meant that I had to refactor a lot, and when it was finally time to implement the chat system, I only had a few hours left (so I just settled for clicking on choice bubbles to switch the state of the generated dialog tree).
It's my first finished Godot game, and I think I learned a lot! For my next project, I would definitely make use of an event bus, and I'd spend more time in my initial planning document considering where and when data and events needs to pass so I can hopefully stamp out surprise bugs earlier.