What I love is that Rachel is aware of them, revisits, and explains why a new opinion has been formed.
being able to say "I was wrong, because" followed by "here is my new opinion based on what I have learnt" is much more valuable than opinion disguised as fact.
Knowing _why_ an opinion has changes is often very valuable.
> Maybe, just maybe, there's some tool out there in the blue void of ideas, that could potentially help managers UNDERSTAND what's going on.
Maybe, but what the article points out is that slapping a metric on something and saying "this is performance" leaves you with a massive quantisation error. If you have a simplistic metric, then people will optimise for it, often simplistically.
The other thing the article points out is that "peer feedback" is often not a useful way to help people. If you were to put your point about those specific tasks in your own feedback, or someone wrote it about you, it would form an indelible mark on your record. Because it'll probably be the only tangible and actionable bit of information, you manager will overindex on that.