I’d like to make an in-universe video overlay affected by the post processing materials I’m using, but setting up a 3d widget is a mess with too many caveats to be worth it. Is there any way to simply add a widget to my viewport but tell it to draw before post effects are applied to the whole screen?
Only to make it a 3d widget. You could attach it to player’s camera. It has own limitation though. Like unable to exclude from camera DOF.
You also could vote for PP enabled UMG feature: UE-16058