I don't know if this is a smarty incompatibility or something, but when I paste the widget code right next another script between the head tags, I get this fatal error:
Fatal error: Smarty error: [in header.tpl line 27]: syntax error: unrecognized tag: "queryString": "", "buttonText": "Support", "buttonColor": "#ffffff", "buttonBg": "#7cb537", "alignment": "4", "offset": "235px", "url": "http://xxxxx.freshdesk.com", "assetUrl": "http://assets.freshdesk.com/widget" (Smarty_Compiler.class.php, line 436) in /home/xxxxx/public_html/admin/libs/Smarty.class.php on line 1088
I suggest something like "inside the <body> tag, just before </body>"