If I view an event on my phone I can see start time for each group A, B, C, D. This allows me to see if the B group is starting with the A group - i.e. Too fast for me !
But on my PC lookijng at the event all i see is the groups available and no start times for each group just the start time of the first group.
The Group section has a little clock symbol next to the number of laps but doesnt show anything on hover via my chrome browser.
Would be an easy change as the data is in your db as i can see it on my Android phone.