I suggest you to add an additional email settings inside the agents preferences. In case an unlocked ticket does reach the pending time - a pending reminder is send to all agents registered for that (my) queue. Yes, right - usually the ticket should be locked by an agent, so that only this agent does receive the pending notification. Unfortunately sometimes agents unlock the ticket which will create a massive spam of...
If a ticket requires customer information, the ticket contact should periodically receive reminders. After a specific amount of days has passed, the ticket status get automatically marked as e.g. "Closed / No Response". No agent-side action required.
The ticket will be set active again, if the customer follows up and answers to the ticket.
If you add "pending reminder" to the "Ticket::PendingAutoStateType" parameter, at pending time each ticket returns to the state specified in "Ticket::StateAfterPending", but the notification mechanism gets lost: i.e. no notification is sent even if "pending reminder" is still set in the parameter "Ticket::PendingReminderStateType".
It would be great if both actions (notification AND state change) could be performed.