In case anyone's curious about how long the submission form has been open each day before reaching the daily submission limit, here's some data. But note that days 1 and 2 are rough approximations, because the form inadvertently closed too early both of those days and had to be reopened later by hand.
Day 1: 10 hours.
Day 2: 12 hours.
Day 3: 16 hours.
Day 4: 18 hours.
Day 5: 14 hours.
When we first floated the idea of having a submission cap to a few friends a while back, people were concerned that it would mean everyone would rush to submit moments after each reopening, so we'd be open for only a few minutes a day. That's a legitimate concern; if the cap were lower or volume were higher, I think it could happen.
But I'm pleased to see that it's turned out that we've mostly been open for at least 12 hours a day; I think that gives a sufficient window for people anywhere in the world to submit at a reasonable time of day.
I'm guessing that the cap will continue to limit submissions per day through the end of next week. But I'm also guessing that by the end of this week, we'll be regularly open for 18 hours a day or more.
One nice thing about the way all this is set up is that it's easily tweakable. We can adjust the cap if we need to, and if it turns out having a cap is a bad idea, we can easily remove it. We'll see how it goes. But so far, I've been pretty pleased with it.