DO NOT use alt-f4 to exit out of PR. This is where 99% of your compatibility problems will come from.
If you exit out properly (hit ~ and type quit, or use the menu) then you should not have any problems. This is because it does not properly unload the shaders_client.zip when you abruptly end the program.
Also I think we may have small problem of changing the crosshair color and disabling auto reload for other mods, but its an easy change in your options. Needs more testing. If you fear PR might have problems with POE2, make 2
BF2 user accounts, one to play PR one to play POE2, I know we had to do that with FH2 cause of some of their changes.
PR has utmost respect for the other
BF2 mods, and we encourage players to try them ALL out, theres no reason players should think they should ONLY play one mod or the other, these are all free content and is the amazing thing about buying computer games - so much free content years after the original game has gotten old.