Pleasantly surprised to see that this even works with interline bags coming coming from another carrier (in this case LH with a 02x bag tag):
While waiting to board the first UA flight of the itinerary (after napping in the LH Senator Lounge -- a godsend)
After Landing in ORD but before sollecting my bag
Currently sitting in the B6 United Club and the results look the same as they did before (even though both the bag and I cleared customs and the bag was rechecked nearly an hour ago) -- would be nice, either to allow visibility into all scan activity as mentioned up thread, or to add an additional step to confirm that the bag has been recorded as being rechecked post-customs