The only browser which actually made improvements to mitigate fingerprint is Tor Browser. It’s basically make all users look the same thus making fingerprint way more difficult. If you need protection against that form of tracking you don’t have other choice. Also, IceRaven it’s just a fork of Firefox which doesn’t lag behind updates. Therefore, it’s highly recommended stay away of it. If you don’t want telemetry then disable it through about:config in Firefox.

If you are looking for privacy and security, Bromite is a good mixture. Way more secure than any gecko base browser.