What are the most important lessons for Dominic Cummings and British civil service reformers?

Please leave your suggestions in the comments, only on-topic comments are welcome.  If you are not quite up to speed, again here is a link to the relevant Dominic Cummings blog post.  Or here is a good summary from The Economist.

After digesting all of your marvelous inputs, I will write a synthetic post of my own, with the best of your ideas and some of mine as well.