Mysql adapter: Changing the STORED status

I encountered an error when using the literal type to change columns.

use Phinx\Db\Adapter\MysqlAdapter;
use Phinx\Util\Literal;

class ContactsGenerated2 extends Phinx\Migration\AbstractMigration
{
    public function change()
    {
        $this->execute('SET unique_checks=0; SET foreign_key_checks=0;');
        $this->table('t_contacts', [
                'id' => false,
                'primary_key' => ['c_uid'],
                'engine' => 'InnoDB',
                'encoding' => 'utf8mb4',
                'collation' => 'utf8mb4_0900_ai_ci',
                'row_format' => 'DYNAMIC',
            ])
            ->changeColumn('c_fn', Literal::from("varchar(255) COLLATE utf8mb4_unicode_ci GENERATED ALWAYS AS (`c_json`->>'$.fn') VIRTUAL"), [
                'null' => true,
            ])
            ->update();
        $this->execute('SET unique_checks=1; SET foreign_key_checks=1;');
    }
}

As long as I change only the json path c_json->>'$.to.something.else', all works well, but changing VIRTUAL to STORED or vice-versa fails with

PDOException: SQLSTATE[HY000]: General error: 3106 'Changing the STORED status' is not supported for generated columns. in /srv/varwwwhtml/glued-skeleton/vendor/robmorgan/phinx/src/Phinx/Db/Adapter/PdoAdapter.php:194...

I think that when the STORED status is changed, the changed column needs to get dropped and recreated.

Start at the MysqlAdapter changeColumn path and the failure reported at src/Phinx/Db/Adapter/PdoAdapter.php:194. Reproduce the migration with a generated column, comparing JSON-path changes with STORED and VIRTUAL changes. Done means changing the generated column's STORED status succeeds rather than raising MySQL error 3106.