Artifacts free version? What do you mean?
There are some blocky artifacts in some dark scenes.
Like in the scene when Luke comes out of the connection tunnel into the room where he gets pelted by Vader and then falls through the window on Bespin.
https://i.imgur.com/Xj0787O.jpg
It’s better visible in motion.
I think that was a masking error or so.
As far as I can remember, Adywan meant that he will fix that with the next release of it, together with ANH and ROTJ.