LTC4380-4 Adjust clamping voltage


I want to protect my electronics from surges with the LTC4380-4. My requirements are:

-Vin = 8-32V

-Vout = 8-40V (max.)

-I = 0.5A

-Surges up to 200V

So, would it be valid to clamp the VCC-pin with a Zener-Diode (Vbr=27V) according to the requirements above?

I am not sure because the internal clamping of the gate voltage(13.5V) would trigger in normal operation since 32V(Vout) +11.5V(Charge Pump) > 27V(Vbr-VCC) +13.5V(Vbr-Gate).

But the clamped voltage of 27V+13.5V-5V(Vg-Th)= 35.5V would be perefct.

Kind regards