And if I turn off "Make known users anonymous so they’re served supercached static files." since PHP is removing the cookies and it get hit before mod_rewrite (?) still PHP is serving the files... I opened an incognito window and log tells me:
supercache dir: /var/www/xxx.com/wp-content/cache/supercache/www.xxx.com/Fetched static page data from supercache file using PHP. File: /var/www/xxx.com/wp-content/cache/supercache/www.xxx.com/index-https.html