[Plugin: Posts 2 Posts] Pass query parameters to get_related()

get_related() is implemented using two calls to get_connected():

public function get_related( $item, $extra_qv = array(), $output = 'raw' ) {
	$extra_qv['fields'] = 'ids';

	$connected = $this->get_connected( $item, $extra_qv, 'abstract' );

	$additional_qv = array( 'p2p:exclude' => _p2p_normalize( $item ) );

	return $this->flip_direction()->get_connected( $connected->items, $additional_qv, $output );
}

As you can see, the extra query vars are passed to the first query, but not to the second, but it’s pretty easy to implement your own version.