Thanks for sharing your thoughts!
As a design thinkers company (from the Netherlands), we use the double diamond principle very often. We loved to go through your version of the double diamond with our team. Now we use your version and added some keywords Iwould like to share with you. For expample; in our projects it’s important to really dive into the context where a company or end-users are in, so we’ve added this context.
Also in the Deliver phase; we added ‘learning’. For us it’s always important to show our client that it is - ofcourse — about Prototyping (what you named building), testing and iterate, but we’ve added ‘learning’ in this row to make clients more comfortable with the fact that making mistakes is oke.
The phase you named ‘implementation’, we now named ‘concept design’, since we think implementation would be after finishing the second diamond.
Let me know when you’re interested to receive our version and more thougths. You can reach me by mailing to email@example.com