How can you sort tickets chronologically, by the last requester's update, from the oldest to the newest?

We tried doing it with Supervisor, but the issue is that a supervisor rule is triggered only once per hour. The idea we had was to use them to help with sorting tickets and responding chronologically - from the oldest to the newest.

So, for example, we set up the following rules:

1. if a ticket is Open and last requester’s update was less than 5h ago - Low Prio

2. if a ticket is Open and last requester’s update was 5 - 10 h ago - Medium Prio

3. if a ticket is Open and last requester’s update was 10 - 20 h ago - High Prio

4. if a ticket is Open and last requester’s update was over 20h ago - Urgent Prio

Now, we also needed to set up a rule to move all of the Urgent, Medium and High tickets back to Low if the next requester’s response is less than 5h old.

Since the rule runs only once per hour, we now have tickets with the last requester’s response in the past hour, still marked as Urgent. 

The Observer rule seems better in this case since it runs only on certain tickets when specified action occurs - but it doesn't have the same options as Supervisor, such as "Hours since created", "Hours since requester responded" etc. 

Does anyone have any idea how to sort tickets chronologically in Freshdesk?!