Does Librewolf have any unique settings?

They’re the ones who make the user.js who decides it. But it changes a lot of the settings so web pages can break.

// PREF: Disable GeoIP lookup on your address to set default search engine region
// https://trac.torproject.org/projects/tor/ticket/16254
// https://support.mozilla.org/en-US/kb/how-stop-firefox-making-automatic-connections#w_geolocation-for-default-search-engine
user_pref("browser.search.countryCode",				"US");
user_pref("browser.search.region",				"US");
user_pref("browser.search.geoip.url",				"");

Will this keep me permanently in the US, whenever I go to a website? Does that website think I am looking at the website from US?

From this place.

I have no idea! I haven’t played with that. Sorry!

No. It makes it so Firefox won’t do a geolookup to see where you are located when providing search results.