I'm sure we've discussed this ad nauseum, but searching didn't yield any results:

I'm waitlisted for an upgrade from Economy to Business on a Saturday morning SFO-IAD on a 3-class 763 in September.

Reservations has me on a "priority waitlist." If I don't clear by the time I can check in online, do I need to arrive at the airport super early in the morning, or should I stop by SFO the day before after checking in online and try to be added to the DM list then. Better yet, can I just check in online 24 hours before and get added to the upgrade DM list automatically?

In other words, does checking in onling put you on the DM list for upgrades that Reservations previously had you waitlisted for?