O proxy reverso websocket é possível com o IIS 8.5 e a URL reescrita 2.0?

Question

Eu instalei o Tomcat como um servidor de aplicativos java por trás do IIS. Usando as seguintes regras, posso reescrever páginas estáticas muito bem, mas, infelizmente, conexões websocket nunca são estabelecidas:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <webSocket enable="false"/>
        <rewrite>
            <rules>
                <rule name="Redirect HTTP to HTTPS" stopProcessing="true">
                    <match url="(.*)" />
                    <conditions logicalGrouping="MatchAll" trackAllCaptures="false">
                        <add input="{HTTPS}" pattern="^OFF$" />
                    </conditions>
                    <action type="Redirect" url="https://{HTTP_HOST}/foo/{R:1}" redirectType="SeeOther" />
                </rule>
                <rule name="Redirect from IIS to Tomcat" stopProcessing="true">
                    <match url="(.*)" />
                    <conditions logicalGrouping="MatchAll" trackAllCaptures="false">
                        <add input="{CACHE_URL}" pattern="^(.*)://" />
                    </conditions>
                    <action type="Rewrite" url="{C:1}://tomcat.contoso.com/foo/{R:1}" />
                </rule>
            </rules>
            <outboundRules>
                <rule name="Redirect from Tomcat to IIS" preCondition="ResponseIsHtml">
                    <match filterByTags="A, Form, Img" pattern="^(.*)://tomcat.contoso.com/foo/(.*)" />
                    <action type="Rewrite" value="{R:1}://apps.contoso.com/foo/{R:2}" />
                </rule>
                <preConditions>
                    <preCondition name="ResponseIsHtml">
                        <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
                    </preCondition>
                </preConditions>
            </outboundRules>
        </rewrite>
    </system.webServer>
</configuration>

Alguém conseguiu isso? A regravação de URL ainda suporta websockets (ws: // & wss: //) proxy reverso?