Interesting. Still feels a bit convoluted though (maybe because built on top of what exists and thus a must).
Groups feels bloated already (always getting lost of who belongs to what - yupp, bad naming, I know). So a foo type approach should maybe mainly be visible from the category. At least a checkbox whether to show those in groups by default.
Too bad Discourse is built with tools I’m totally unfamiliar with. At best I might create utilities that accesses the database directly. Which other people seem to do much better with their scripts anyway. Oh well, maybe when I retire 
.