I just investigated this. The indicator does not move by 'force', but by direct displacement of the center plunger. There is a safety feature, which I have never run into, to prevent a complete crushing of primers.I have this one as well. Bought it for the indicator and all the "crush .xxx" hype, but took it apart and found a spring inside. The real magic of this tool is it pushes the primer in until it bottoms out and the tension or crush is determined by the force it takes to compress the spring. All primers are seated to the same preload no matter their height.
Try this to see for yourself. Set it all up and seat a primer to "0", then keep going till the indicator stops moving, which is about .004. Then keep pressing. The lever keeps moving, but the indicator doesn't. That's because you're compressing the spring
For instance, If I place a case only partially into the shell holder and raise the plunger into the case head, where it is stopped by misalignment, the handle can be squeezed further. BUT, the indicator does not move with further handle squeeze at that point. It is stopped right where the plunger is stopped.
So the indication of crush IS correct, regardless of force applied.
Attached patent drawing.

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