The ability to change email contents, both for having reminder 2 being different to reminder 1,also allowing each event to have its own reminder templates.
E.g, first reminder might say ‘this is your first reminder,if you wish to clear your sign up please do so before the 2nd reminder due x days before the event’ and the second might say ‘this is your final reminder and you are now confirmed to attend and cancellation is no longer possible)