Some MOSFETs have a built-in ESD protection in the form of back-to-back Zener diodes between source and gate.
An example can be seen here.
This particular MOSFET has a Vgs(max) spec of +/-12V. Unfortunately, no spec is given for the Zener diodes so I don't know how they're rated.
I am wondering if it's possible to apply a higher Vgs than the maximum amount specified, given that a series resistor is used between voltage source and gate.
I have a sample of this MOSFET, so I wired it with a 10 kΩ series resistor on the gate, applied a bench PSU between resistor and source, and connected a multimeter between gate and source.
Plotting Vin vs Vgs:
I did the same with a 910 kΩ resistor in series instead of 10 kΩ (which is closer to the value the real application would use):
I've run the setup with the 10 kΩ series resistor and 60 V input overnight, and the MOSFET seems to still work (Rds still changes accordingly to Vgs), though I am clearly going above Vgs(max).
Does anybody have any insight on this being a good practice?
EDIT: I am aware that external zener is the proper way to go, but it has a cost and requires a space. I am asking for previous experience from someone that possibly have been in the same situation before.