next wrinkle:
have the cdiv202-av cable installed. I have to say that the apple VGA to lightning adapter has a painfully short cable and that lightning extension cables stupidly expensive, but that's not the wrinkle. Just a complaint.
What I'm experiencing is what an 'incompatible USB' error message when plugged into the vga lightning adapter but not when plugged into the stock lightning cable that's plugged into that is plugged into the downstream USB cable coming from the cdiv202-av cable. only when that cable is plugged into the apple VGA adapter and the output of that adapter.