ProxyPass and Streaming profile on the same VS

Which version of LTM and the ProxyPass iRule are you testing? For ProxyPass v10, you'd need to set $static::RewriteResponsePayload to 1. If you want to customize the find/replace strings in addition to the ProxyPass datagroup definitions, you'd need to modify this section to append your new find/replace pair(s):

    Check if we're rewriting the response
   if {$static::RewriteResponsePayload} {
       Configure and enable the stream filter to rewrite the response payload
       Hide the command from the iRule parser so it won't generate a validation error
         when not using a stream profile
      if {$static::RewriteResponsePayload > 1} {
         set stream_expression_cmd "STREAM::expression \"@$host_serverside$path_serverside@$host_clientside$path_clientside@ @$path_serverside@$path_clientside@\""
      } else {
         set stream_expression_cmd "STREAM::expression \"@$host_serverside$path_serverside@$host_clientside$path_clientside@\""
      }
      set stream_enable_cmd "STREAM::enable"
      if { $static::ProxyPassDebug > 1 } {
         log local0. "$log_prefix: \$stream_expression_cmd: $stream_expression_cmd, \$stream_enable_cmd: $stream_enable_cmd"
      }

If you want more specific steps, can you confirm the versions you're working with and what in concept and when you're trying to do the response content rewriting?

Aaron