[rurounijones]

As a user there is nothing that drives me to rage more than a company arbitrarily (from my POV) marking a ticket as closed.

Having read your post I can see the merits but if I were a user who does not know about your workflow it would make me very angry.

Why can you just not have the ticket auto-close after your reply and X days have passed, you can change your internal list to only show tickets that are open and last updated to by the customer?