I did something really similar a few times between about 2010-2017 and wrote about it in 2017. "DIY 360° review: how I asked colleagues for anonymous feedback about myself": https://troy.yort.com/diy-360-review-how-i-asked-colleagues-...

I sent it to some friends as well.

When I first did this, I couldn't find anyone else who had shared that they did it. That's the main reason I wrote about it - to make it a bit more approachable for others.