Just to add a datapoint, perhaps just some fluke.
This year I intentionally booked my vacation trip to Belize as overnight at ORD, since we have missed our connection the past couple years and spent the night at IAH anyway.
Normally, I like the 8:20am on Fridays out of IAD, but it usually leaves an hour or so connection. This time I found a good price on DCA->ORD (arriving 9:40p and ORD->BZE (leaving at 9:25a) so decided to give it a try. Yes, it was a few minutes under a 12 hr layover.
Checking one bag at IAD (the other was for the overnight, just in case), the agent looked at the bag tag that printed behind the counter and said "checking to Belize City?" I confirmed, "will it go through, or do I need to pick it up at ORD?" and she said it would go through. I checked "Track My Bags" several times once we got to our room at the ORD Hilton and it never showed it going to a baggage carousel.
If I can do this consistently, we definitely preferred the relaxed approach of planning the overnight stopover.