Ultimately I found that this simply could not be done with my current configuration. I was, however, able to work around it by wrapping my valid html5 page in an object that was then embedded in the iframe. In IE 9 this seemed to allow my page to render in the iframe in standards mode and use the SVG transforms that look clean. I created the following wrapper aspx script:
<%@ Page Language="C#" %>
<%
string url = "app/path";
if(!String.IsNullOrEmpty(Request.QueryString["path"]))
url = HttpUtility.UrlDecode(Request.QueryString["path"]);
url += "?i=1";
if(!String.IsNullOrEmpty(Request.QueryString["id"]))
url += "&id=" + Request.QueryString["id"];
if(Request.Browser.Browser!="IE"||Request.Browser.MajorVersion!=9) {
Response.Redirect(url);
}
url += "&quirky=1";
%>
<html>
<head><title></title>
</head>
<body style="width:100%; height:100%; margin:0; padding:0; overflow:hidden;">
<object type="text/html" data="<% =url %>" style="overflow:hidden; width:100%; height:100%"></object>
</body>
</html>