Brilliant resource, IMO. There’s a lot of activities, you pick the ones (if any) that suits your requirements. Honestly, if you cannot see the value of brainstorming an idea, and you never done it before, not sure if you fully understand people. These activities can be prepared in a way that are well informed and take more or less time. I tend to see them as good additions if everyone understands the value it brings. What I’ve came to see is that sometimes people disagree, but are proven differently later in the process (at that point, it meant going back and re-think all the initial assumptions).