Not sure if this was shared yet:
http://www.nytimes.com/2016/12/27/movies/how-rogue-one-brought-back-grand-moff-tarkin.html

nothing new really, but nice to see some official words on the matters.

I still question if they did full mo-cap for Tarkin’s face, which those images seems to imply they did, because the impression i got from the viewing the film (both times) was that he looked like he was hand animated. I can only call it ‘dobby-face’, as there was a scene that looked just like the same level of dead-eyed-cgi that dobby had in the harry potter movies. They probably did touch up the performance by hand afterwards, even if they started out with mo-cap.