Experiment setups never work for Hamilton, it's strange they try it over and over again and only for Hamilton. First stint on soft was a big waste as well, so useless. Didn't matter it the end anways but it can cost them in other races places. Tyre degradation is a big problem this year. It's like Ferrari and Mercedes have swapped. Their last big strength is gone.
We don't actually know this. We only know the unsuccessful outcomes when they mention it was an experimental set-up. When it is successful, they only say things like, "...the car performed well and was consistent in blah blah blah."