I can understand that argument. Could the ‘sender’ of the PM not be changed so that it comes from the moderator who requests revision? Though, I suppose that can invite personal hatred/dislike towards that moderator if the user disagrees with their point.
I think it would be a lot more friendly for the user to simply just reply to the PM rather than having to create a new message to site moderators. What happens in the case where the user is less than TL2 and the site restricts users of that and below from creating PM’s?
I guess the latter seems the only viable option if you don’t intend to break practices with system PMs.