it seems to me that option isn't "queried" by postfix or something else..
The entries in the sql-db aren't "USED". And with that i mean the entries in
grommunio.forwards
MariaDB [grommunio]> describe forwards;
+--------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+------------------+------+-----+---------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| username | varchar(320) | NO | UNI | NULL | |
| forward_type | tinyint(4) | NO | | 0 | |
| destination | varchar(320) | NO | | NULL | |
+--------------+------------------+------+-----+---------+----------------+
https://github.com/search?q=org%3Agrommunio%20forward_type&type=code
@mwilliams @jengelh can one of you confirm or deny that please?