You joke but that's all also import rehearsal for all the teams responsible for each stage of the flight. The compleat plan, in full detail, with the "expectation" that it will happen is essential to learning.
If you don't start practicing these details until later in the development you have missed an opportunity to fine tune them and prepare for all eventualities.
If you don't start practicing these details until later in the development you have missed an opportunity to fine tune them and prepare for all eventualities.