I had a few classes like that, decades ago; and I agree that they were the best in terms of curbing cheating. Stressful as all hell for those with anxiety issues, but the format also made some honors students become exposed for the frauds they were.

In retrospect, I think the format is still the best but I would remove the narrow time limit. Give the students a whole day to try; and so not artificially filter out those with anxiety.