Ernest,
Thank you for your quick response with such specific code fixes. Im happy to report that your suggested changes indeed fixed the varnish issue right away (you can see it in action on a dev environment here: http://varnishcheck.getpantheon.com/varnish/develop-preit.pantheonsite.io). Since we manually altered the plugin files we will be holding off on updating until this fix is included in an update. Thank you again