Solid read! An additional resource for OKRs is a book called “Radical Focus” by Christina Wodtke. Here is a link to it on goodreads: https://www.goodreads.com/book/show/28951428-radical-focus
He has a lot of respect in the tech world, being a leader at Kleiner Perkins who invested early in Google, Amazon, and many others. He's the person who really popularized OKRs, so the book has some great examples.