What a fun read -- clever and well-plotted and full of inventive magic and characters. I love the clock and Elfrida and Tufty et.al., and I enjoy Albus's manipulations -- definitely for the greater good this time. And of course, I love the role Minerva plays; "redoubtable," indeed.
So many fun touches, like washing the "feminine sanitary supplies" (I think this is the first story I've read that mentions wizarding practices in this area, and it's exactly the sort of thing inquiring minds want to know). I also like the idea that a Squib like Mrs Figg might have a certain level of magic; of course this makes perfect sense. You paint a clear picture of the difficulties Squibs would face in such a world, yet Mrs. Figg never loses her dignity and strength.