We've sliced NavigationTiming by a few criteria in Grafana (browser, location, etc.) but combining different criteria is impossible, making investigation of NavigationTiming improvements or regressions tedious and often fruitless. We also often need to slice things by new criteria and it's cumbersome to set up a new set of metrics for that.
Overall it seems like Grafana isn't the right tool for the task. Pivot and its ability to add filters, break down by facets, etc. seems to be much closer to what we would need. @Nuria do you think Pivot would be a tool appropriate for this job? If so, what would it take to feed NavigationTiming data into a "data cube"?