The shrinking of the sides of Yoda’s mouth has always looked odd to me, even when Ady did it in ESB:R. But it is a bit more lifelike, so it’s a tradeoff.
Another thing that might make him more like the ESB puppet would be to reduce the highlights in the eyes.
The mouth movements may need to be a little more subtle. I don’t mind the highlights myself, but it could be worth a try.