I shamefully don't know much about Indian or Pakistan history beyond the broad strokes, and while the episode don't expand on that basic knowledge, it did help provide the emotional impact of that terrible situation during Partition in August, 1947. The painful confrontation between Prem and Manish at the end resonates with today's world of divided people and demonstrated how we're still not learning from the mistakes of the past.
As a personal story for Yaz, this episode provided a touching story about her nan and a secret family history that Yaz had to learn from her own perspective. While the episode touched upon the classic "don't rewrite history, not one line!" trope, I liked how The Doctor her companions ultimately didn't have to do much to avoid effecting history in the end. I enjoyed watching Yaz struggle with the realization that there was a monumental part of her nan's early life that did she had no idea about and how Yaz continued to struggle with that ignorance as she watched history play out in front of her, feeling helpless every step of the way. And while I enjoyed the bookending scenes in present day between Yaz and Umbreen, I do wish Umbreen had acknowledged that she knew Yaz was somehow actually there beyond her understanding and that's why she passed on the watch to her (unless that's what did happen in the last minute of the episode, my feed cut off on me and didn't return until the episode was over).
While I liked the twist of how the Kisar weren't actually assassins observing and the mourning the tragedy of premature death, I ultimately found their presence rather superfluous to the events and I'm left wondering why they were needed. I don't wonder this just for the sake of wanting a pure historical, but also because I think the story could've been much more powerful if Partition played by itself while The Doctor discovered on her own what would ultimately happen to Prem without being told by the Kisar.
On a side note, the Kisar's death observing reminded me of something and I can't quite put my finger on it. And no, it's not Marvel's The Watchers that I'm trying to recall. This is going to bug me until I figure it out.