He constantly works on the structure and talks and acts like he has been indoctrinated, just like all other people around the stone.
Once freed from the indoctrination during the quest "Cleansing the Stones" he remarks "I'm asking myself why Miraak was making us build these shrines... and I'm afraid the answer will be far worse than any of us can imagine." and return back to the Abandoned Building in Raven Rock with Bralsa Drel.
If the mines have been reopened at the conclusion of the quest "The Final Descent" he finds a job working there and mentions "Brasla's been nice enough to show me how to swing a pickaxe. She is an old hat when it comes to digging up ebony. I may not be an expert at it yet, but it's good to be back to work and have some coin in my pockets."