Careful, mode 2 means reject all or fall back to accept all if there is no Reject All button. So use that only if cookies are disabled or otherwise controlled, for example by an AddOn like Cookie AutoDelete. If not, rather use mode 1 that hits only a Reject All button if available but ignores others.

See https://community.mozilla.org/de/campaigns/firefox-cookie-banner-handling/ and https://github.com/mozilla/cookie-banner-rules-list