I was able to reduce the WR time by about 20 second by discovering a bug that allows you to use the linking book to Atrus without entering the pattern into fireplace. The linking book is already there behind the wall before entering the pattern. You can't see the book if you poke your head through the wall, but it's still there and manipulable. So you can just reach through the wall to open and enter the book.

MOD EDIT: retimed to 1:38.842