Yes. A 2 Day Showcase can be plenty grueling. Lots of reps, lots of playing with high adrenaline. Then there are all sorts of factors you cannot control (such as it turns out to be playing in 90+ degree heat, or how much the kid played recently with his travel team, or travel delays that can eat into sleep/rest etc). I would stay away from 3 straight days of Showcasing, if at all possible.