Don't see why - it really isn't difficult to look at where the plane bounding Z2 is, and to see which side of it the transformer is.I see. Don't you think that your response to his questions/comments about his concerns will have simply confused him?
You call it academic.I also would imagine that, even if it doesn't have much/any actual significance, a good few people would probably disagree with your academic argument that the 'back parts' of a flush-mounted accessory are not in Zone 2 even if the face plate is.
I call it simple physical layout and what the regulations actually say.
