Building with architects - experiences, tips?

Yes, I think so too. But the 1-2 weeks are of course very ambitious. However, it is not entirely unreasonable that the planning takes a few months. I would have claimed that it usually can (should) take 3-6 months. If you start from zero and plan individually?

That's a joke. Up to 1 year for service phases 1-5? He would be out with me. 90% is just downtime where Typ 2 is busy with other projects and not available to you