I think it kind of depends. I've stopped using canvasblocker a while ago though because it messed sites up and honestly, I want to show that I'm using linux so that sites can see that desktop linux PCs exist and we're alive and well. So being more unique for analytics is kind of a double edged sword. If I really want to be anonymous then TOR or maybe mulvad browser would do the trick.

They don't but canvasblocker is unnecessary https://github.com/arkenfox/user.js/wiki/4.1-Extensions

Afaik, no conflict.

Been using both together for years.

Both. Try adding privacy badger, trace and chameleon as well.