Lovely post and the idea of reading books twice is awful. No matter how important the book is.
Preferably, going over the book for references is a great idea and acceptable.
Life is really too short to digest a book twice now that it’s obvious that not all the words used by the author is important.
Specifically, the idea is what matters in all cases.
So read with intent, read with understanding.
Take cogent points away from the book by jotting it down in a notepad or what have you.