Custom platform to build custom query

[fzerorubigd]

I want to have a custom platform for pgsql, mostly for create index on LOWER(key)
For this I create a new platform (Just to fix my problem, not a very generic code):

namespace {

    /**
     * Class CustomPgsqlPlatform
     */
    class CustomPgsqlPlatform extends PgsqlPlatform
    {

        /**
         * Add a table to list
         *
         * @param Table $table table to add
         *
         * @return string
         */
        public function getAddTableDDL(Table $table)
        {
            $ret = '';
            $ret .= $this->getUseSchemaDDL($table);
            $ret .= $this->getAddSequenceDDL($table);

            $lines = array();

            foreach ($table->getColumns() as $column) {
                $lines[] = $this->getColumnDDL($column);
            }

            if ($table->hasPrimaryKey()) {
                $lines[] = $this->getPrimaryKeyDDL($table);
            }

            $sep = ",
    ";
            $pattern = "
CREATE TABLE %s
(
    %s
);
";
            $ret .= sprintf(
                $pattern,
                $this->quoteIdentifier($table->getName()),
                implode($sep, $lines)
            );

            if ($table->hasDescription()) {
                $pattern = "
COMMENT ON TABLE %s IS %s;
";
                $ret .= sprintf(
                    $pattern,
                    $this->quoteIdentifier($table->getName()),
                    $this->quote($table->getDescription())
                );
            }

            $ret .= $this->getAddColumnsComments($table);
            $ret .= $this->getResetSchemaDDL($table);


            foreach ($table->getUnices() as $unique) {
                $ret .= $this->getUniqueDDL($table, $unique);
            }


            return $ret;
        }

        /**
         * Add a unique field
         *
         * @param Table  $table  table to add
         * @param Unique $unique unique field to add
         *
         * @return string
         */
        public function getUniqueDDL(Table $table, Unique $unique)
        {
            $list = array();
            foreach ($unique->getColumns() as $column) {
                if (!$column instanceof Column) {
                    $column = $table->getColumn($column);
                }
                if (strtoupper($column->getType()) == 'VARCHAR') {
                    $list[] = "LOWER(" . $this->quoteIdentifier($column->getName()) . ")";
                } else {
                    $list[] = $this->quoteIdentifier($column->getName());
                }

            }

            return sprintf(
                'CREATE UNIQUE INDEX %s ON %s (%s);',
                $this->quoteIdentifier($unique->getName()),
                $this->quoteIdentifier($table->getName()),
                implode(",", $list)
            );
        }
    }
}

The configs are ok, and php load this class, but for building the sql files, phing use the old platform file
here : https://github.com/propelorm/Propel/blob/master/generator/lib/config/GeneratorConfig.php#L167

So the first time, one instance is created from my class, but in the real sql-task, it use the propel version of this behavior.

I don't know is this a bug or its normal, and if its normal, how I can use my custom platform for building query for insert-sql task?