Yeah welcome to the state of the art in measuring AI impact. I have contacts at a few different larger tech companies that are fully AI pilled (the one I work at included) and every single one has forgotten the last 50 years of lessons in measuring dev productivity and hyperfocused on PR throughput and token usage.
Fun fact: all the data I've seen suggests at most a 50% uplift in those metrics. And that's at the top percentiles. Its very clear that the already high performers see the greatest uplift but anyone in that meaty middle will only see incremental gains.