Not that it helps much, but that is certainly (and unfortunately) something I have come to find / feel as well 
I know Roon can / should support singles and EP’s but in my mind it struggles when compared with albums, which it’s pretty good at. Maybe that’s just because the metadata available for Albums is better / more available / more consistent.
But you only need to look at a site like Discogs to realise how much music there is old and new that doesn’t fit into an album centric model.
Maybe tighter integration with a platform like Discog might be the solution to this longer term, there’s already a couple of feature requests for this. Maybe worth adding a vote or comment over there.
btw. I’ve read multiple forum posts and KB articles since I have been a Roon user. But I’m yet to find to find a really good & definitive document from Roon on exactly how we should handle singles, EP’s, DJ mixes and the like. Maybe I have just missed it, but I’d be interested to know if there is one other than the general KB article on the metadata and tagging best practices which only lightly touch on non-album centric music. Hope I’m not hijacking this thread, but be interesting to knows is such a (definitive) post or document exists, other that the ones linked to above.