Track Service Rep First Response Time Automatically functionality

Track Service Rep First Response Time Automatically  A feature in Summer '26 is the above new metric which was designed to "Eliminate complex workarounds, uphold customer satisfaction KPIs, and ensure SLA compliance with a new metric that captures the exact moment a service rep sends their first reply in a messaging session. Service Rep First Response Time is now a value on the MessagingSessionMetricType field of the MessagingSessionMetrics object. Previously, identifying the actual moment a rep sent their first message required complex LWC development or API callouts to the ConversationEntry object."      However, testing of this appears to show the figure measures the time from the Messaging Session being created, to the moment a human agent first replies - so this includes the customer's initial interactions with the bot, customer inactivity time, time sat in the queue etc.  Should it not be the time difference between the first message minus the time it was assigned to the agent, to measure the individual Service Rep's service, similar to the other metrics?   Alternatively would a better design not have been to simply capture the date/time of the first human message and then we could have used formula fields to calculate the two metrics using the existing created, assigned and accepted date/time fields in Omni (1. total wait time to speak to a human & 2. how long the human took to send a message after accepting the MS).      In short, is there an easy way to derive how long a human took to send a message after accepting a MS, as this is what we were hoping "Service Rep First Response Time" metric would show us but it doesn't.    @* Service Cloud *