Originally Posted by
AlreadyThere
I base this on my application of GPUs to family members, which work exactly like that. They start towards the top in case a bookable seat opens up, but as soon as the standby list is generated, they drop to their individual status (well down the list).
I don't understand this comment at all. The standby list is "generated" when pax start checking in (which can be prior to T-24 for connecting pax), but it is not used to process upgrades until the flight goes to the gate, which is typically inside of T-1. Prior to the flight going to the gate, upgrades are processed pursuant to the "invisible" list which, by definition, is one that we can't see (though there have been very recent reports this list, or some variant, is displayed when UA tries to induce pax to buy an upgrade at check-in).