I have finally been reading the last part of The Book of Dust, and honestly I admire Pullman for trying to examine mental health and marginalised people through the lens of daemons. There are lots of interesting little moments that are really well realised
However, I do not think this was a good thing to explore through a story about Lyra becoming a boring adult and having to go on a quest to find 'her imagination' which for some reason involves falling in love with a man eleven years older than her who met her when she was a baby
Malcolm Polstead is fine in the first book when he is a kid, but in the two following novels he is both a university lecturer and a spy, and incredibly competent at all times. He comes off as both a Mary Sue and a bit of a self-insert
Also the villain of the piece is Lyra's uncle, who worships his sister (Lyra's mum) who died in the original trilogy. He is somehow high up in the same organisation as the sister but never once mentioned in the original trilogy