Is VarioS float switch reversible?

I have the VarioS 2 Circulation Pump as my return pump. I was considering using the float switch as a shutoff to stop the pump when the sump runs dry, as in a water change. The float switch is configured to shut off if the water level rises, as it would for a skimmer pump.

The product description says it can be used either way, but the pump didn't include instructions for this. Most float switches have reversible floats, but if I reverse the float on this unit, it turns off at the top and off at the bottom and is only on in the middle. This is a problem, because if the pump ever turned off, the sump level would rise as water drains from the display, and then it would never turn on again...

Seems like the magnet/sensors aren't aligned right. Can this float not be used for low water level in a sump?