I feel like a box set (or other releases which contain multiple other whole releases) should probably be treated differently than say, greatest hits compilations and selector comps (as RYM calls them, basically an unmixed compilation of material by various artists). the main reason being box sets are more useful for the completionist collector, whereas other compilations might more cater to the more casual fan just wanting the hits

I don't really have a preference whether this is a new secondary release group type or a release group attribute (once we have those), but I think there needs to be some way to display them differently.