Good points.
I understand the first from a process perspective. What I don't understand is why it could work against both parties. If the recipient is going steadfastly to refuse to send the read acknowledgment having opened the email, the time is still ticking against them and CASA already has the 'delivery receipt'.
But in any event the system your wife is using seems much more 'streamlined' and doesn't depend on the recipient going through the manual process of ticking the 'read receipt' pop up.