SET column on ENGINE=DuckDB silently drops any member at ordinal position 9 or higher

INSTALL SONAME 'ha_duckdb';

CREATE TABLE t1 (id INT PRIMARY KEY, s SET('a','b','c','d','e','f','g','h','i','k')) ENGINE=DuckDB;

INSERT INTO t1 VALUES (1,'h'), (2,'i'),( 3, 'k');

SELECT id, s FROM t1 ORDER BY id;              

SELECT id, CAST(s AS CHAR) FROM t1 ORDER BY id;          -- id=2 correctly shows 'i'

SELECT id FROM t1 WHERE s = 'i';                          -- correctly matches id=2

13.1.0-opt>INSTALL SONAME 'ha_duckdb';

Query OK, 0 rows affected (0.076 sec)

13.1.0-opt>CREATE TABLE t1 (id INT PRIMARY KEY, s SET('a','b','c','d','e','f','g','h','i','k')) ENGINE=DuckDB;

Query OK, 0 rows affected (0.008 sec)

13.1.0-opt>

13.1.0-opt>SELECT id, s FROM t1 ORDER BY id;   

Empty set (0.003 sec)

13.1.0-opt>INSERT INTO t1 VALUES (1,'h'), (2,'i'), (3, 'k');

Query OK, 3 rows affected (0.005 sec)

Records: 3  Duplicates: 0  Warnings: 0

13.1.0-opt>SELECT id, s FROM t1 ORDER BY id;   

+----+------+

| id | s    |

+----+------+

|  1 | h    |

|  2 |      |

|  3 |      |

+----+------+

3 rows in set (0.002 sec)

13.1.0-opt>

13.1.0-opt>CREATE TABLE t2 (id INT PRIMARY KEY, s SET('a','b','c','d','e','f','g','h','i'));

Query OK, 0 rows affected (0.010 sec)

13.1.0-opt>INSERT INTO t2 VALUES (1,'i'); -- fine on InnoDB

Query OK, 1 row affected (0.001 sec)

13.1.0-opt>SELECT id, s FROM t2; 

+----+------+

| id | s    |

+----+------+

|  1 | i    |

+----+------+

1 row in set (0.000 sec)

13.1.0-opt>

13.1.0-opt>INSTALL SONAME 'ha_duckdb';

Query OK, 0 rows affected (0.072 sec)

13.1.0-opt>ALTER TABLE t2 ENGINE=DuckDB;

Query OK, 1 row affected (0.016 sec)                       

Records: 1  Duplicates: 0  Warnings: 0

13.1.0-opt>SELECT id, s FROM t2;    

+----+------+

| id | s    |

+----+------+

|  1 |      |

+----+------+

1 row in set (0.003 sec)

13.1.0-opt>