Would be nice if there was a setting to activate automatic send of the e-mail "user_email_body_offline" upon change of registrant status from "Waiting list" to "Waiting". Also if the event is setup with creditcard payment, it would make sense mails are sent automatically about that the user is now on the registrant list, and a payment link to pay.
I just had this implemented. Please submit a support ticket so that I can send you the package which has this feature so that you can try and give us the feedback
For adding link to allow users to click on to make payment, just insert [PAYMENT_LINK] tag into the email message
