RootCauses Artifact is slow if there are lots of "SVG changed" invalidations about lighthouse HOT 3 OPEN

Definitely reproducible, looks like we are truing to get the node details of every layout invalidation node which is taking a while.

from lighthouse.

For me Lighthouse takes ~4 minutes locally on https://lottiefiles.com/
Some optimizations in the root causes engine helped get that down to ~2:45 (~2 min of which is spent in root causes)

We should continue to iterate on the performance of the root causes engine, but https://lottiefiles.com/ also contains a lot of invalidation tracking events (specifically iframe added to dom events) that the root causes engine has to sift through. We may want to limit the root causes engine somehow since it's results are helpful but not vital.

from lighthouse.