Solution for MOSFET tail cap?

Saw the design on OSHPark…let me to the datasheet…uses a cargepump capacitor for the voltage to activate the MOSFET

https://oshpark.com/shared_projects/62Q3bnak

I too was looking at trying to design a reverse polarity MOSFET passthru type addon for inline chargers just to protect the chips that don’t have built in reverse polarity protection
got the idea from this video

https://oshpark.com/shared_projects/62Q3bnak