[MrE]

I'd guess this probably works great with stationary tanks.
For any tank that moves, unless they have some signal smoothing or stabilization mechanisms built into the unit, the sloshing/stirring of the liquid level in the mobile tank can result in laser detector signal errors, thus, unstable readings.

The desired dampening rate is adjusted with dip switches right on the unit to reduce fuel slosh and gauge bounce by adjusting how fast or slow the gauge reacts to the fuel level change.