The Quartet, the New Trilogy and Unstable Truth.

Hello Rabbi, I started reading your quartet after I finished Truth and Unstable.
I noticed a certain difference in the presentation of things: in Truly and Unstable you talk about how it is possible to reach truth but not certainty, and you actually go against the assumption that truth = certainty. But in Two Carts you put them together in one piece (at least according to what I've read so far), has anything changed between the books?
This question concerns a somewhat broader question, in light of the release of the new trilogy: Is the Quartet still "relevant"? Do you still agree with what you wrote there or did you write the trilogy in order to introduce a new sub-genre? By the way, I haven't read the trilogy yet, but I still wanted to ask to know.
Thank you very much and happy holidays