Good stuff. I’m a fan of being very clear and upfront about the goal and stage of the project prior to beginning any work.
How do you know whether the test is worth pursuing further? Do you establish goals or criteria ahead of time of what the test needs to prove as part of the pre-mortem process?
Are you familiar with the ‘Double Diamond’ model? Think it might be interesting for you, there is definitely some overlap in the approach https://www.thoughtworks.com/insights/blog/double-diamond