One reason is that transaction performance could be very different, even regardless to data volume. Your points are all correct of course, but then that wouldn

One reason is that transaction performance could be very different, even regardless to data volume. Your points are all correct of course, but then that wouldn’t be a preview environment, would it? It would be shared database state in a database staging environment. Which, for what it’s worth, is also how I have seen this problem managed when it came up. As for costs, maybe true, but it could also take a lot longer than an hour to bring up a large deployment. And if every engineer is doing this for one hour a week, and you have a few dozen engineers, there’s a 2x cost increase with a tougher capacity planning problem since your load is now tied to your hiring plans.