I'd like to add `{action.optOutUrl}` token in emails, but this token is replaced by empty string. I think it is legitimate to use this token because it does not refer to a mailing-list, but to an opt-out of all communications. I often use this extension in combination with CiviRules and I think it is now very useful to create automations (with the delay option) that move away from the basic concept of transactional email.