Yes, in theory we can add this functionality, i.e the ability to modify facial expressions I will put this on our list.
However, unfortunately there is no support for phonemes atm... implementing this is a huge task, since there is (AFAIK) no out-of-the-box solution available that's compatible with our audio engine (FMOD). But the game performs some fake lip-movement for bandits when they talk, for example - it's not the greatest solution, but usually it's sufficient...
You're probably asking for phonemes because of this? It looks awesome and very promsing btw! We could provide an API method to enable the "fake" lip movement if that helps?^^