Ok, I see what you are saying. What you describe sounds like what I want. For instance, in the game I am working on we have a global PP that I use to make corrections for the game as a whole. is completely independent. Then when it starts raining the PP from your system fades in some settings and desaturates the scene/gives it some rainy day vibe. It doesn’t completely overwrite the global PP volume I already have, just the settings that have been edited (at least that’s how I believe PP volumes behave. Tell me if I am wrong).
Maybe I misunderstood though and is not what you meant. If is something the user will have to do on their own, that’s fine. I just thought it might be cool to customize whatever PP you wanted per weather and then fade those values in with the PP blend weight.