Whether the tau correction is applied depends on where the system is being deployed.
If the system is to be used in shallow, coastal waters where large vertical gradients that change quickly are expected, the tau correction should be applied, as it accounts for the response time and puts the interface between two different water masses in the right place.
If the system is to be used in deep water (>200 m) where the vertical gradients are small, the tau correction should be turned off - in areas where the gradients are small, the calculation adds more noise.