But the whole point is that except in unusual circumstances discussed above (F upgrade seats released during OLCI window), it doesn't matter when you check-in for a flight, since everyone is on the waitlist regardless of what time you check in, and the waitlist is processed at the 3 hour mark, or at the gate, by elite status, then fare class, then date of ticket purchase. I think the odds of you exactly "tying" with someone on all 3 of these metrics are 0%, so time of check-in doesn't matter.