Creating a healthy working environment is the key for a strong creative design process! And it is so good to read it from a team manager! Working overtime and long meetings felt to me most of the time counter-productive, but it was always hard to expose my opinion, because this is what rules design studios... As you write in your article, you managed teams but you also have been managed by superiors. All points mentioned came from learning from both sides. You consider both experiences having the same value, and it is a big prove of open-mindness and humbleness. But sometimes team managers never worked as "workers" or they just simply forgot this experience....How can I tell to my team manager that well-being can only be positive for the a creative design process? One thing for sure is that I could make them read this article :) do you have any other suggestions?

That a hard task, for sure. I personally found that only when I was in the position, I could try to do differently. One can only hope their bosses will be interested in their well being as much as in the project. However, it is also important to define limits early on. If you are always available for all-nighters and weekend work, this will signal that you are somewhat fine with it. Make sure to define your limits, and show that you can do better work in your own terms.