If you extract the latest SO zip (with Custom.css 4.53), and cut and paste semorg.kollabor's Features Page, the Boostrap 4 "cards card-columns"
div does not work.
Tweeki skin is based on Bootstrap (v3.4.1 or v4.4.1 via opt-in).
Must LocalSettings be amended to enable SO to opt in?
SemanticOrganizationHooks looks for the following $wgTweekiSkinUseBootstrap4 = true; $wgTweekiSkinUseExternallinkStyles = false; $wgSemorgUseCustomTweekiFiles == false;