1 / notification.verbosity is not documented. Here is a blurb you can copy paste :
`notification.verbosity` Int, Define the verbosity of notifications, use 3 to spam your channel to death (everything is notified) up to 0 for less notifications (only tasks related)
2 / According to the doc, the channel(s) to join should be read from `$this->getConfig('notification.channels');` and not from `$this->getConfig('join');`