Haha yeah we implement 'soft time-boxing' by tracking git commit timestamps. It's not as stressful as having a visible timer and we won't block a submission that exceeds the recommended time, but reviewers can clearly see who took longer and their last commit within the suggested time, which helps to create an apples-to-apples comparison.
No candidate wants to be entered in the Hunger Games for who has the most time to sink into a take-home.