I did this for Forgotten Hope 2 when I used to play, and found I got a slight performance boost through that method.
So far this isn't working for me in PR. I've done the same thing as with FH2, turned off in game AA, and set up an AMD profile like so.

I'm using the PRBF2.exe found in C:\Program Files (x86)\Project Reality\Project Reality BF2
There is no in game effect. Any thoughts on what I'm missing here?
For comparison, here are my FH2 settings

