Today, if a ticket moves from the status New to a status of Pending Assignment, the system counts that as a response for purposes of the "First response" metrics. We intended to use "Pending Assignment" as a sort of holding tank: New (customer wrote the ticket but we've not assessed it yet) -> Pending Assignment (we've seen the ticket and it's due to be assigned) -> Assigned (we have a specific agent working on it now).
In our workflow we did this via an automation rule - a ticket was set to Pending Assignment by the rule and an email was sent to a group of triagers who are then tasked with assigning it. However, because of this, all of our tickets had a First Response time of around 2s since the rule ran very quickly on every ticket. We ended up with a weird scenario where our average first response time was very low, lower even than our average time to assign, which doesn't make sense, since assignment comes before response in most cases.
It'd be good if Pending Assignment did not count as a response, or even better, if this was an option we could choose (let us choose which statuses count toward which metrics).