The common wisdom is that Zener diodes are suited for only very low power surge protection because of their low current capacity.
But what about where it was used as a sacrificial device for clamping transient spikes? Surely there would be a very brief period (ie in the order of microseconds) where it shorts completely across the pn junction and the internals become molten but remain temporarily physically intact.
Other typical surge components seem to rely on a massively larger transient current response - for example, the leads on MOVs and the traces on the PCB would normally be capable only of a few amps yet they're usually rated in thousands of amps.
So what kind of instantaneous current handling could you expect from a Zener diode?
Edit: In this particular application, the zener is already used as a voltage regulator. TVS diodes don't seem to be used for steady state voltage regulation - are they unsuitable or is because of cost?