control double opt-in from form settings

At the moment, you can choose the type of opt-in on a form but it would be goo to be able to have conditional logic to determine whether a double opt-in email gets sent at all. I know they can ignore it but if they explicitly say they don't want marketing material and you send them an opt-in email anyway, it looks a little unprofessional. I'd rather they just get marked transaction only, as that is still a valid status for that form.