Ability to adjust email subject line and content when sending invoices to patients or third party

It would be great to be able to adjust the subject line and email message when emailing invoices to patients or a third party such as work cover etc.

Insurance companies usually require the case number and name of the person involved in the subject line. Not providing this can delay payments.

Also, it would be good to be able to adjust email content for each invoice sent via this method to give instructions to patients or a third party for various reasons.

Hope this can be an update very soon.