Love my digital calipers and the ability to switch between metric and English at a touch. Now some have a third mode, fractional. The ultimate digital caliper for modelers should have all that and also the ability to enter a scale factor and read directly the scale size..and then flip to see it in millimeters, inches, fractions, etc. Technically (speaking as a one-time digital designer) it is not difficult to do. The only way to get this function today is to buy a really high-end digital caliper with a computer interface. Then you have to drag a cable and computer around as you work. Cumbersome and expensive. Should be self-contained. Maybe we modelers can get a movement going and interest a caliper manufacturer in such a project.