Aye, I figured it was tricky. But, an idea nonetheless. Thank you for confirming that.
My only last suggestion then is to re-tool the PM-User option under the flag button to be used in relation to the other flag options. That is, suggest or warn a user (as the examples I have above in my OP) and also have it logged somewhere for staff. That way it will be made clear if something needs to be escalated (because with the PM-User option, it was broached gently by a user before mods have to be involved), and that paper trail if needed.
That way, the PM-User feature under the flag button can strictly be used to maintain order and not toward the discussion itself.
@DeanMarkTaylor I will be watching that now. Thank you for the notice! 