The opt in checkbox is labeled "Enable Javascript"
https://fingerprint.com/blog/disabling-javascript-wont-stop-...
https://github.com/jonasstrehle/supercookie
Interestingly when I go to https://noscriptfingerprint.com/ all I see is a blank page. My browser is pretty locked down in other ways which probably helps, but I'm still taking that as a good sign.