Indeed, if we (at DL, which uses a similar computer system, I think) missed the cutoff by even a minute, we had to use manually written bag tags, which take longer to write out, which means it usually wasn't worth the effort ... not to mention I never felt confident the bag would get routed correctly with a manual tag on it.

It's simply not fair to push the bag cutoff deadline. If your bag goes down late and misses the flight (the loader took the last on-time bag and drove off already), the airline usually ends up paying for the delivery at the other end, even though it wasn't their fault.