I don't recall Mimara ever having a first person section, but she is indeed written in present tense.
To be honest, with the exception of Mimara, the WLW, and Kellhus-in-the-Outside, I've become inclined toward the stance that Bakker is simply becoming more experimental (and confidant) in his approach to the narration of the series. The perspective becomes increasingly loose as TUC goes on, and by the final chapters, there are small sequences and paragraphs here and there that are entirely detached from any character, and even from the "thematic voice" of the typical omniscient narration that we are accustomed to, on a level not seen anywhere else in the series thus far. So I'm not sure how much stock to put in the particularities of perspective in the latter parts of TUC. I think, for example, that a lot of the second person stuff during the finale was simply a way for Bakker to really put the reader right there at Golgotterath, witnessing the No-God and the Second Apocalypse firsthand.
Then again, there's also something fishy about, well, everything regarding Moenghus Jr. and Cnaiur's relationship IMO, and the use of second person (which we otherwise have only seen from Kellhus-in-the-Outside and Koringhus's musings) may well be intended to imply some sort of cosmic shenanigans -- but for now my impression is that RSB is just getting very, very comfortable with his style of narration in this series. And really, if there's any point in the series to be experimental and novel with the storytelling, it's in TUC.