Confirm there are not already settings or features that do what the shop is asking for: I have checked and found that we do not have the option to edit or delete or it seems that the message is coming from Redo that shows at the bottom of the order confirmation emails.

What does the shop want the product to do: Shop have an inquiry about the order confirmation emails. They wants to know from where the notes is coming . Also, they want to change the notes. However, the option is not available.

Why/how would it improve sales or efficiency: It will send the correct information to the customer also give them the ability to edit themselves.