I was wondering if anyone else has been thinking about this issue: With a voiced protagonist, any new lines spoken by him/her would have to be silent or recycled from the original voice acting. Unless you can find a convincing voice actor with a similar voice.
Do we have any quest/dialogue modders here who have plans for dealing with this? Full sentence dialogue options that are silent would be the easiest option and also gives you more freedom in what the player character says. At the same time, there are so many generic 'I will do what you are asking of me' protagonist lines that re-using or editing those voice files could kinda work.