I have found that it works well as an open-endlessly dynamic process when you are doing the kind of work that the people who came up with Scrum did as their bread and butter: limited-term contract jobs that were small enough to be handled by a single pizza-sized team and whose design challenges mostly don’t stray too far outside the Cynefn clear domain.

The less any of those applies, the more costly it is to figure it out as you go along, because accounting for design changes can become something of a game of crack the whip. Iterative design is still important under such circumstances, but it may need to be a more thoughtful form of iteration that’s actively mindful about which kinds of design decisions should be front-loaded and which ones can be delayed.