The machine does not have to be in the place where the concourse meets the terminal, so maybe the machine can be bigger, maybe giving efficiency gains. No pass

The machine does not have to be in the place where the concourse meets the terminal, so maybe the machine can be bigger, maybe giving efficiency gains. No passengers are involved like they are at carry on screening, so also this might yield efficiencies, as you don't have to keep a bag and passenger near each other. As you suggest there are fewer banned items in checked bags, so less bag opening needed.