I'm thinking, specifically, of the Falcon 9, where I read from their specs that the entire structure is coated with an ESD-conductive paint.
I was also under the impression that the launch vehicle's (LV) electrical reference was its chassis. Again, according to their specs, the paint surface is grounded to the vehicle's structure.
What happens, then, if surface current is induced on the vehicle's skin due to (indirect) lightning? The chassis of the vehicle is closer to the internal electrical links than is the skin. Why would you risk return current through your system's grounding?