As far as I am aware, there are only 3 competitions that have Am v Pm sessions.
Mfta + Nefta witner seasons and the Gp series?
The rest of the years competitions usually see shooters all on the course at approx. the same time.
Nefta & mfta is over (mostly) for 2014/15 so too late to look at the results, but if I can get the information about who shoots what session in the Gp series, I will grade as normal and run a separate Am v pm set of graded results. Then provide the difference after the Euro.
If shooters feel it needs changing after that, you can see if your region will take it further.
Personally I am on the swings and roundabouts results