Tried the 4k version and it’s very impressive! Well done.
The only minor quibble is that the scrolling text is a bit stuttery, but I’m guessing it’s just not possible to get it smooth and maintain the “correct” framerate.
The FX sequences though - wow.

I’ll check my Sky recording tomorrow and report back. The only slight concern is that I think it’s an episode from around season 4. As has been mentioned by Artan42, the latter episodes are visually superior in the first place. What that means is that in order to make a fair comparison, you may have to test your approach on the same episode as I am capturing. Let’s not jump the gun though, and wait to see what I manage to get first!

Also I was wondering if you’d be happy to share what software etc you are using to do this?