I thought the same. When I remember to use a timer, I find it very motivating, but the breaks are easily filled with email, switching contexts, getting a drink, going to the bathroom or whatever else.

Maybe a purely structured chat would work - summarise what you achieved, outline what you will do in your next allotment. But anything beyond that might be time better spent planning and prepping for the next session rather than wasting the first minute getting up to speed?