Solution to stop Submersible Pump running on empty

My Lunar Lexon has a Truma Ultrastore pressurised water system with a submersible pump. When the Aquaroll empties the pump continues to run until switched off. The pump light is on the control panel just inside the door - it’s easy to miss it when alight and it’s almost impossible to hear the pump running when inside the van.

I’m considering installation of one of the following two products to reduce the likelihood of burning out the pump.

1. Mid Service Centre Self-Calibrating Pressure Switch

2. Pump Saver timed cut-out switch

Has anyone experience of either of these products please, or have any alternative solutions?