It depends. Many addons have effects that can be tested for and fingerprinted, but it’s not always straight forward. There’s a way to detect any specific chrome extension, but doesn’t work on firefox because it uses unique extension ids per person.

With addons like CanvasBlocker, they generate random values for a bunch of apis like canvas. So each time you will look unique, but it changes every time so you’re not easily tracked. I’d assume it’s similar to what Brave does, but I haven’t looked into the details. Some stuff isn’t randomized by default, so they can get info like timezone and languages, but probably not enough to give you a unique identity.