Running Workout Buffer Zone

I just started using the run workouts on Zwift with the 2020 tri academy and noticed it is extremely hard to get the stars on the 100m recovery intervals. I’m not exactly sure how Zwift is selecting semi-finalists, but hopefully it’s not based on completed stars and FTP/ threshold pace.

However, is there some way to implement a buffer/ neutral zone with visual indicators after speed changes on the treadmill? Say the first and last 10-15 metres of an interval are not counted towards the star and this gives the treadmill a chance to speed up/ slow down. Maybe there already is a buffer zone, would anyone have extra info on that?