Just a few things I've been thinking about since reading the book:
Geralt 'of Rivia': I believe Geralt previously claimed he chose Rivia at random, but the Mother Assumpta being 'of Rivia' herself struck me as interesting. They have a conversation about names, and whether Geralt should add something, etc. Did he name himself after her, or am I being too hopeful? I kept thinking there would be a reveal, especially when her illness appeared.
Also, Geralt has another dad 🥹 Granted Preston is not exactly the best fatherly figure, but there are some good moments. I really like the fact that Preston did seem pained over kicking Geralt out of Rocamora; the lack of sleep, bags under his eyes, the later statement that he saw the (assumedly pained) expression on Geralt's face. The fact that he tells Geralt that he essentially needs to accept his 'defects.' "You must come to terms with your own imperfection." “And I wanted to save you.” "I remember the expression in your eyes. But I had only one thing on my mind then. That I was rescuing you. Saving you."
In the same vein: "I regret what I did." Judging from the fact that this phrase from the execution is repeated in the letter, I am assuming Holt said that out loud for Geralt's ears, and that makes me feel things.
The whole 'need to see the ocean' motif: The fact that both Nenneke and Preston knew that this is what Geralt wanted is so sweet to me. '“Only Kaedwen?” she said in surprise. “And you so wanted to see the ocean, I recall."' “...Moreover, it’s time you saw the sea you so long for. And something of the world.”
I also enjoyed the expansion to the pogrom lore (what a sentence to write), particularly the four witchers joining arms to form a sign. The signs I feel aren't explored that much, so it's nice to see a further indication of what they are capable of (even if its rather horrific).
Vesemir having details of the foundlings' parents: Geralt later says he asked Vesemir about Visenna, and I am now assuming this conversation arose after Geralt's own conversation with Preston, as Geralt claimed at that point that Vesemir hadn't revealed anything to him.
Artamon wanting to vivisect Geralt, and Geralt's quest for revenge against those that hurt him: the Geralt and Ciri parallels go hard.
Lastly, the fact that Geralt essentially became a postal worker for three months post-murder is so funny to me. I know it serves a purpose (hiding), but it just feels so side-questy to me, very Geralt.