Thankfully, my laptop departed from Zhengzhou and arrived at Incheon overnight. So it seems to be moving happily again. The cause for my confusion were twofold:
1. A vague customs-related notification out of Louisville on November 1
2. No intermediate scans or reassurance that they knew where the package was in the one week it was in Zhengzhou.
Really, that confusion comes down to very poor communication from UPS. If they had let me know "hey, this is in outbound China customs and we need it to clear" or "this facility is very backed up, we're still processing and it will be out as soon as we can" I would have been a lot less worried about it.
Amusingly, the "investigation" UPS opened yesterday about my package's whereabouts remains open. The international shipping guy I talked to on the phone was very insistent that the package was actually in Louisville. Whoops.