LAVFilters-0.66-35-git-r3563(ac6065a)
http://tmod.nmm-hd.org/LAVFilters/
Classic Theme Restorer 1.4.3beta12
https://addons.mozilla.org/ja/firefox/addon/classicthemerestorer/versions/1.4.3beta12
[new options > General UI (1)] 'about:preferences window appearance' v1&v2 for tabs
Note: General > Homepage > 'Use Current page' will always add 'about:preferences' as homepage, because thats the only page currently opened in the new window.
No difference to browsers default preferences ui with only preferences tab open.