That can give false positive result, someone ask you for advice and you say "report it to moderator, write this in comments: (insert comment)".
This sounds like a mdayonliner-style "mentoring" excuse

Not if you receive PM asking you "what to do, do you know how to report this?" and then you say "when reporting, write
this in comments". I only say it can give false positive, not that it is giving. I have bunch of those PM's deleted so I can't really give you example.
According to Occam, the probability of a "fake newbie" (born knowing everything about forum's inner workings) asking a seasoned scammer for advice on reporting posts would be similar to the probability of said scammer having a confidential source for all this shit that he comes up with.
Yes, that's why I said
there is probably nothing which will convince me that PM7 and QS are not alt accounts.