[gruez]

On firefox you're probably better off using container tabs + temporary containers. With that, you can basically have a separate browsing session (cookies/website data) per tab, which allows for isolation and doesn't require a whitelist to work (unlike the approach described in the OP).

[wumpus]

How does that prevent browser fingerprinting?

[gruez]

privacy.resistfingerprinting for that. As for how sugarcoat protects against this, it's unclear. They only mentioned patching out localstorage.