Re: XMLRPC and a Poster's IP address.
Just managed another way by patching bbPress’ xmlrpc.php and overwriting $_SERVER with the desired value.
// Poster IP
$_SERVER['REMOTE_ADDR'] = isset( $structure['poster_ip'] ) ? $structure['poster_ip'] : $_SERVER['REMOTE_ADDR'];
Then what I do on the bbPress Mobile side is send the data:
$params_array = new xmlrpcval(
array(
"title" => new xmlrpcval($title, "string"),
"text" => new xmlrpcval($text, "string"),
"forum_id" => new xmlrpcval($forum_id, "int"),
"tags" => new xmlrpcval($tags, "string"),
"poster_ip" => new xmlrpcval($_SERVER['REMOTE_ADDR'], "string")),
"struct");