- Log in as member and create new topic
- Log in as admin (note this admin shouldn't have linked accounts or turn of the setting Allowed Groups to POST AS another member) and edit that topic.
Now topic author is Guest
BTW the above setting is not displayed correctly on ACP
$form->add( new \IPS\Helpers\Form\Select( 'la_groups_postas', \IPS\Settings::i()->la_groups_protected == '*' ? "*" : explode( ',', \IPS\Settings::i()->la_groups_postas )