My conclusion then was that the speedometer 2.0 benchmark is dominated by page load, because it does that a zillion times as it goes through all the different todomvc implementations.
The lastpass performance tax shows up mostly during page load.
The question is, how representative is the speedometer benchark of normal use?
But I don't think it is entirely unrepresentative of real world performance.
If your hypothesis is correct — if you have LastPass installed, your pages are probably going to load slower and you'll experience a longer "uncanny valley". The tax paid is worse for pages that are otherwise lightweight.
You might want to look up that term sometimes. It means something different than you seem to think.
See https://www.fastly.com/cimages/6pk8mg3yh2ee/3Toq5jWy0EuqG8KU...
Where does it originate if I may ask?
https://addyosmani.com/blog/rehydration/
https://developers.google.com/web/updates/2019/02/rendering-...