All my lights are 3 wire. All my backline amps are as
well. I was actually planning on grounding / bonding to one of the lifts as opposed to the truss. There is a metal to metal connection between the stand and lift.
My electrician thinks I’m crazy so I’ll probably drop the whole thing. She’s a total perfectionist and thinks this is over the top...
It seems to me, there is a different thought process between an electrician that deals with installed power (i.e., buildings) vs "entertainment" power - theater, outdoor events, etc. Grounding seems to be fairly "automatic" in industrial settings where one would have specific grounding points on steel truss, metal building skin, versus the myriad of possible problem points in a festival, carnival, or theater venues.
YMMV