I don’t think the lock makes sense for this use case. If you upgrade your SuperDeluxe Pingmaster 4000 Sonar Pinger to the new 4000s model (analog-to-analog audiophile quality pings!), you have to replace hundreds of dollars worth of e-readers (costing hundreds of thousands of dollars at standard military markup rates) instead of just paper manuals.
I’m not sure the added security makes it worthwhile. (Of course, I am assuming a rational quartermaster. In reality, where the choice is between “minor changes to existing technologies to yield realistic if incremental security increases” and “entirely new and expensive technologies that yield novel security problems while creating a false sense of safety,” we know which option the government likes to take.)
