> the identifier can also persist [...] as long as the Firefox process remains running

Make sure to exit Tor Browser at the end of a session. Make sure not to mix two uses in one session.

Or shut down and boot tails again. You need privacy? Take your time.

Anyone that serious about opsec should have dedicated hardware for that anyway

Why not tails in a VM?

because your host might be compromised

the vulnerability was fixed upstream by mozilla anyway

Use a separate machine for these stuff, never mix your clean machines with the dirty ones, complete separation, different networks

better yet, disable javascript when using tor.