The exchange between the two is amazing and I would have loved to see Krennic try to bring Galen to his side of thinking in a couple of flashback scenes. This also could have given the film more time to develop Galen as a character so that his death would be more impactful.
Definitely recommend Catalyst, Krennic is the best part of the book.
Funny you should say that as I was planning to pick it up in the next 3 weeks. Knowing that Galen purposefully crafted a weakness in the Death Star makes the premise of the novel 100 times more enticing to me. Also knowing exactly what he felt whilst keeping up his facade should be interesting as well.