Discard all Overprints
I work specifically in digital prepress for POP displays, and never use overprinting at all. Removing overprinting from a document can be a hassle as I work with documents that almost always contain a mix of solid objects, linked raster images and other things. I consider myself extremely lucky when I find a document that I can easily remove all overprints from in one go
Illustrator already has a "Discard white overprints" in the document setup (although I rarely use this menu). We should either have a menu option to remove all overprints from a document, or at least an option in the document setup to remove ALL overprints instead of just white.