I use layer comps and Artboards a LOT. The company I work for request multiple sizes of Social Posts for various platforms, and I usually create 3 or 4 variations for use at each size. This allows me to template a single file, change some text and a key image or two and i'm ready to go. The multiple sizes are created using Artboards, and the variations use LayerComps, but I can only export either LayerComps, or ArtBoards. I end up having to export Artboards and repeat the process for each LayerComp. I have had up to as many as 16 LayerComps for variations in messaging and imagery, with ArtBoards off and on, depending on which messaging will be going on which Social Media platform.
I'd love to be able to Export LayerComps with a "Use Artboards" checkbox that would then export each ArtBoard for each set of LayerComps, all at once.
I'd be extremely happy to learn I can do this already and I just haven't figured it out yet, but otherwise i'd love to see this feature added.