function set_max_mem( $memory ) {

    if ( function_exists( 'ini_get' ) ) {
        $memory_limit = ini_get( 'memory_limit' );
    } else {
        // Sensible default.
        $memory_limit = '128M';
    }

    if ( ! $memory_limit || - 1 === $memory_limit ) {
        // Unlimited, set to 32GB.
        $memory_limit = '128M';
    }

    $memory_limit = intval( $memory_limit ) * 1024 * 1024;

    $memory_limit = $memory_limit * 0.5;
    $current_memory = memory_get_usage( true );

    if ( $current_memory >= $memory_limit ) {
        $return = true;
    }

    return false;

}

add_filter( 'wpf_batch_memory_exceeded', 'set_max_mem' );

function set_time( $time ) {

    return 10;

}

add_filter( 'wpf_batch_default_time_limit', 'set_time' );