Moving clients on authentication failure

I want to move a client if she didn't pass my url authentication.

e.g.

    <mount>
        <mount-name>/mount</mount-name>
        <authentication type="url">
            <option name="mount_add"    value="http://some/url"/>
            <option name="mount_remove" value="http://some/url"/>

            <option name="listener_add"    value="http://some/url"/>
            <option name="listener_remove" value="http://some/url"/>
            <option name="auth_header" value="icecast-auth-user: 1"/>
        </authentication>
        
        <!-- 1st example. Moving to other mount -->
        <on-authentication-failure>/othermount</on-authentication-failure> 
        <!-- 2nd example. Playing pre-recorded file -->
        <on-authentication-failure>/sorry.ogg</on-authentication-failure>
        <!-- 3rd example. Firstplaying pre-recorded file, then play the stream anyway (or move to other mount) -->
        <on-authentication-failure>sorry.ogg+/othermount</on-authentication-failure>
    </mount> 

Especially the 3rd example looks difficult, but I'd say it's a legitimate use-case to tell the listener that she didn't authenticate properly and is now getting e.g. a lower quality stream.