I love this and expect most of our users will love it too. Unfortunately, the mismatch in opacity highlighted by Keegan is also the thing that’s holding me back from adding it to our instance:
I actually prefer it in the other direction, where the user profile and flair remain full colour, however I agree that the real issue is the mismatch between opacity of flairs and profile pictures.
The other three points from Keegan elegantly sum up everything else I was thinking.
Can’t wait to see more development on this 
Edit:
Comment from a colleague:
I like it! So much that I would even be interested in being able to choose that having it active is the default"