It’s not really a menu item, but I love Obatzda
You can also do it with the normal settings menu (about:preferences). The setting is called “Enable Firefox Sync” under the tab “LibreWolf”. Might be a bit easier this way.
You can reenable that in the settings, but it’s off by default. I use it everyday
Looks interesting, but I would’ve really liked some gameplay. From what’s being shown here and on gematsu it somehow looks like a mixture between Observer and Bioshock (only universe, not really gameplay).