I once had a chance to look over filmed aeronautical engineering drawings for an old Ryan Trainer. The copies had been purchased from the Smithsonian.

All the drawings were filmed at a standard setting, then reviewed, those too dark or light were re shot with the settings adjusted based on the previous results, then added to the end of the roll. This struck me as a pretty good method to get through a large count quickly.

Someone mentioned Microtek's scan wizard. It's alive and well on new model Microtek scanners. It's auto cropping feature works, and the software operates with one touch once a good config is found. File naming is automatic on the order of yourtext###.tif or jpeg or whatever.