Camera PP vs. PPV

What is going on here exactly? Camera PP and PPV (unbound) seem to interact with Play mode (PIE, SIE, etc.) to render different image effects to the viewport. I find this deeply confusing and there doesn’t seem to be a global controller for post processing. Could someone elaborate on this distinction at a high level?

What is the global controller for post processing in UE4: is it the camera or the PPV, or are the two competing with each other?

while i cant give you a high level explanation i may have found something to help out a bit. if you select the camera and g oto the camera setting section in the details panel. there is a post process blend weight. this should allow you to disable the post process settings of the camera

I definitely appreciate your input. I will experiment with this as well.