I have been told that Rec.gov will be releasing cancelled reservations each day at 10 AM eastern, 7 AM Pacific time. But for a while, the reservations outside the lottery were being released at midnight Eastern time. I have several reservations to release, and when I do, I'll be sure to try to see when the number available changes for the particular date.
I imagine this information will cause a 7 AM scramble for permits throughout the summer.
I suppose someone could start watching the permit availability and see if numbers do pop up at 7 AM.