I'm really not quite certain of this PM thing. In the simulator, it has never failed to amaze me the blank looks and scratching of heads that goes on when you ask the captain to carry out the first officer's after start checks (just to see if he knows what is going on on the other side of the centre pedestal), and if you ask the first officer to carry out the captain's after start checks.
It is as if a line is drawn down the centre of the cockpit and whatever goes on on the other side of that line is secret men's business.