@kims
Mulling it over, I don’t have a good term, and find myself wanting two different ones:
Sounds like not the situation you’re in, but there’s one version where the wasted day is totally the right call: The client understands their request is probably a bad idea, but the cost of proving it fails as expected is low while the benefit of it succeeding against all odds is high. In that situation, it would be foolish not to go ahead and prove out the expected failure a bit.
And then there’s the other version where the client is just stubborn and not listening to expertise, and they need to be able •react• to the thing they’re unable to •imagine•.