In order to have access to the ICS feed for calendars in Drupal you need to use the numeric ID of the calendar in Drupal's database. Rather than trying to wrangle some half baked workaround for this on the Drupal side. The path of least resistance seems to be to add this value to the locations data. In practice these values are only going to change if an entire calendar is deleted and re-created which is pretty unlikely.
In order to have access to the ICS feed for calendars in Drupal you need to use the numeric ID of the calendar in Drupal's database. Rather than trying to wrangle some half baked workaround for this on the Drupal side. The path of least resistance seems to be to add this value to the locations data. In practice these values are only going to change if an entire calendar is deleted and re-created which is pretty unlikely.